Of Demons and Slayers

A/N: Oh boy, please prepare yourself for the longest Author's Note ever, of all time. Hello, everyone and welcome to my new story: Of Demons and Slayers. This story is a crossover between the Halo Franchise and Doom (2016), but the interesting part is that it already exists as a sequel of sorts to my other story, Universal Doom, which is a crossover between Doom (2016) and a multitude of other franchises as well. Technically, this story could alternatively be titled "Universal Doom: Chapter 20". So, if you are reading this and you haven't read Universal Doom through chapter 19, please know that there are a few aspects of this story that you may not understand. I'd recommend reading Universal Doom up until that point and then reading this, but if you do not want to, then the story will still hopefully stand on its own, so no worries! Please also note that this story will take place during the events of Halo 3, just to give you a reference of what is happening. OK, this has gone on long enough. Without further ado, please enjoy the first chapter, and let me also remind you that I own neither of these franchises!


They let me pick. Did I ever tell you that? Choose which ever Spartan I wanted.

You know me. I did my research, watched as you became the soldier we needed you to be.

Like the others you were strong, and swift, and brave. A natural leader.

But you had something they didn't, something no one saw but me.

Can you guess?


Was I wrong?

Sergeant Major Avery Junior Johnson gazed through the foliage, taking time to light his cigar before turning around to his Marines behind him.

Early this morning, they had been sent out on what was supposed to be a reconnaissance mission, but little did they know that they would find the big guy himself in the jungle foliage.

"This ain't good," one of the Marines said, his eyes locked on the unmoving form.

"Damn," said another. "How far did he fall?"

"Two kilometers. Easy."

Sergeant Johnson frowned.

"Stay sharp!" he said authoritatively, and the Marines immediately stood to and set up a defensive perimeter around the small crater that they currently occupied. Sergeant Johnson felt an internal sense of satisfaction watching them. They had been trained well, and even though it seemed like humanity was on the brink of extinction, his Marines did not falter.

A corpsman knelt down next to the rigid armor lying in the dirt and took out a small data pad. Wordlessly, he ran a few scans on the armor, muttering to himself as he tapped a few buttons. Johnson walked up behind him.

He took a puff from his cigar and spared the figure a glance before turning to the doc.


"His armor is locked up," the doctor said while typing away on his data pad. "Gel layer could have taken most of the impact…"

His voice held uncertainty; a tone Johnson never enjoyed. The corpsman typed a few commands on the data pad, and the armor suddenly relaxed. The figure's arms fell limply to its sides. Sergeant Johnson knelt down next to the figure and gazed into the golden visor, looking for any sign of life underneath the armor. There was none that he could see.

"I don't know, Sarge…"

Johnson exhaled in resignation, cigar smoke billowing from his nose. He then reached behind the figure's helmet. With a small tug, he pulled free the data crystal that was locked back there. He saw that it was empty, and he sighed.

"Radio for VTOL, heavy lift gear," Johnson said in resignation, still looking at the crystal in his hands. "We're not leaving him here.

Johnson nearly jumped out of his skin when a gauntleted hand grasped his arm from the forest floor.

"Yeah, you're not."

Relief flooded Johnson's entire body as he turned to see the Master Chief attempting to stand.

"Crazy fool! Why do you always jump?" Johnson teased as he used both hands to help the Chief to his feet.

"One of these days you're going to land on something as stubborn as you are! And I don't do bits and pieces!"

The Chief said nothing. His gaze had been drawn to the data crystal in Johnson's hand. The empty crystal was supposed to house an A.I., a special A.I. that was now no longer with them. The Chief wordlessly took the crystal from Johnson.

"Where is she, Chief? Where's Cortana?"

The Chief did not answer immediately but continued to stare at the crystal. Johnson tilted his head impatiently.

"She stayed behind," the Chief finally said. Johnson was no expert on Master Chief mannerisms, but he detected a solemn tone in the Spartan's voice. He could understand why, as he shared the feeling.

Thel 'Vadam treaded lightly through the forest. He had to regroup with the humans, as they had not much time before the brutes would home in on their position.

'Stinking, vile beasts,' Thel thought to himself as he brushed through the foliage.

The san'shyuum were fools to ever consider them for admittance into the Covenant. Their barbaric race had been on the verge of annihilation when they had been discovered, and now, the Covenant stood on the brink of extinction due to their ineptitude. While Thel was not unhappy that the brutes had weakened his former masters, he was still exasperated that the prophets had not seen the incompetence of the dishonorable jiralhanae. Those beasts were not worthy of dying to his blade, and Thel felt as though he was dragging himself lower every time he ran one of them through.

Thel's camouflage was active, rendering him virtually invisible to the naked eye, and it seemed none of the humans noticed as he arrived at the edge of the small crater they stood in.

He was mistaken. One had noticed.

Before Thel could take defensive action, the large Spartan had grabbed a human pistol and charged at him.

"Chief, wait!" Sergeant Johnson yelled, but the human did not stop. Thel deactivated his camouflage, and the Spartan grabbed him by the shoulder and jammed the pistol into his mouth. Thel instinctively clenched his four mandibles around the weapon, but he knew that it was pointless in the current situation. If the Spartan chose to fire the weapon, Thel's shields may or may not have been sufficient enough to stop the bullet. Kinetic weapons were primitive, but they were still lethal.

Thel chose not to move. If he made an attempt to get away, the Chief would likely fire the pistol, and Thel would not have that. Not when there was vengeance to be had.

"The Arbiter is with us!" Johnson called. The Chief said nothing, but kept the pistol where it was, seemingly daring Thel to make a move against him. Thel patiently remained still. He would not die here. To be killed by the Demon in an attempt to aid him… Thel found the situation rather ironic as well as dangerously dishonorable.

"Come on now," Johnson said, grasping the Chief's right shoulder. "We've got enough to worry about without you two trying to kill each other."

Slowly, the Chief removed the pistol from Thel's mouth. The Sangheili stretched his aching mandibles in response and met the Master Chief's gaze for the first time since their meeting on Halo.

The last time they had seen each other was in the clutches of the Gravemind, back when the Prophet's shroud of lies still covered Thel's vision. The parasite hive mind had forced them to work together to stop the firing of the Halo array, and after joining forces with Sergeant Johnson and the human female, Miranda Keyes, Thel had succeeded in halting the firing sequence. The Chief had been sent after the Prophet of Truth, and that had led him here after the Prophet had fled to Earth.

"Were it so easy," Thel said, speaking directly to the Chief.

The Master Chief did not look away from Thel, and although the Sangheili stood nearly a head taller than the human, that did not detract from the unease that the Spartan imposed upon him. This human was directly responsible for Thel's failure in protecting the first Halo ring, and he had killed many of those under Thel's command in the process, dishonoring him and his house immensely. Only one other human had managed to be such a nuisance to Thel during his time as a Covenant commander, but he was fairly certain that human was now dead…

Admiral Margaret Parangosky sat at her desk, thinking deeply about the events that had led to this moment. Across from her sat a large machine: a pedestal of sorts which was surrounded by overarching sensors and projectors. The pedestal itself was inscribed with numerous runes and drawings, a feature that Parangosky did not understand the function of. Its addition had been insisted upon, however, so Parangosky had agreed in favor of what this machine would supposedly bring her.

"Is everything ready for activation, VEGA?" she asked.

"Yes, Admiral Parangosky," came a calm and all-around pleasant voice from the A.I. on her right.

"BB?" Parangosky added.

"Everything is in order," came the voice of Parangosky's personal smart A.I. from a different terminal.

BB had been her personal A.I. for a few months now, and Parangosky had grown comfortable around him, an honor shared by few humans and even fewer A.I.

Unlike other A.I., BB had not chosen a human avatar as his holographic image. Instead, he sat as a cube, a plain and simple box that was rather suited to his full name: Black Box.

VEGA, in a similar fashion, did not choose to appear as a holographic human. Instead, he chose to appear as a circular symbol that Parangosky did not recognize. Perhaps it had been a symbol assigned to VEGA by his previous masters.

Parangosky thought back to when VEGA had first been delivered to her. One of her lieutenants had deposited the data crystal in her hand and had told her that a Spartan-ll had dropped it off. Not just any Spartan-ll, though. As made apparent by her lieutenant, this delivery had been made by the Master Chief himself. Her curiosity had been peaked, and Parangosky had wasted little time accessing the chip and meeting VEGA.

VEGA had informed her that he was from a different dimension than her own, that he was originally an A.I. that was used to monitor all functions on a Mars research base, and that he had been saved and brought here by an entity he called the 'Doom Slayer'.

Parangosky had immediately dismissed VEGA as a rampant A.I. upon hearing such a far fetched story, but upon viewing the multiple schematics and advanced functions that the A.I. possessed, her view had changed. VEGA had then proven that he was not just any old smart A.I. He possessed higher functionality and potential than any of the A.I. that Parangosky had ever seen. Therefore, she had been inclined to hear out the rest of his tale.

VEGA continued by saying that the Doom Slayer had given him to Doctor Catherine Halsey on Reach. The Slayer's motives were currently unknown to VEGA, but he did know that it was Dr. Halsey that had given him over to the Sierra-117 for delivery to ONI.

Parangosky had been relatively surprised by the news, which was really saying something, since she was hardly ever surprised any more. Halsey had given this super-A.I. to her of all people? Surely Halsey knew that Parangosky loathed her with a deep passion…

Parangosky had then asked VEGA questions of her own: What was the dimension he was from? What was the UAC? And most importantly, who or what the hell was this Doom Slayer that he had been referring to?

VEGA had proven to be completely compliant, answering any and all of Parangosky's questions without a hint of resistance. When he detailed the Doom Slayer, Parangosky's interest yet again peaked.

VEGA told her everything that he knew. The Slayer's theorized origin, how the UAC had found him, and what events had occurred since:

"Tell me, VEGA," Parangosky had said. "If this 'Doom Slayer' of yours is so hell-bent on killing all the demons, then why was he here in our dimension? We don't have creatures like that here."

"I hypothesize that coming here was not his direct intention," VEGA had replied calmly. "The tether system in his armor may have malfunctioned and accidentally sent him to this universe. He may or may not still be in this dimension, but if he possessed some sort of mechanism to activate the tether from within his suit, it would cause him to jump to another universe at random."

"And why exactly is that?"

"The tether system developed by the UAC operates in a remote fashion. The item that is being transported between dimensions possesses a tether uplink, but it is designed to only be activated by a homing beacon at its destination. The homing beacon activates the tether remotely and guides the item through dimensional space and to its location. Without a beacon, the tether will make a jump randomly when activated. There is no rhyme or reason as to where it is dropped off."

At that point, the gears in Parangosky's head were already turning. If what VEGA said was true, then this Doom Slayer was even more powerful than even the Spartans that already existed in this universe. In fact, the physical feats that VEGA had depicted the Slayer as some sort of superhero. And if VEGA's recounts of the Doom Slayer held even a shred of truth, then he had potential to be a great asset to Parangosky. Possibly even the greatest asset she ever wielded.

"VEGA, do we possess the technology in our universe to build one of these homing devices?"

Nearly a month later, VEGA had successfully helped Parangosky build a homing platform. During that time, VEGA had demonstrated to Parangosky just how powerful of an A.I. he actually was. His processing capabilities and ability to multitask was beyond anything any other A.I. in this universe was capable of.

The process of building this device was kept secret even from Parangosky's most trusted lackeys. Even the young Serin Osman was kept out of the loop. Osman, despite her aptitude and likelihood of being Parangosky's successor, was not quite trustworthy enough with something as potent as this, and Parangosky had not come this far by taking unnecessary risks.

The crews that had been contracted to build this machine came from multiple agencies, and a single crew was only contracted to build a certain piece. Parangosky was not daft enough to give one single crew an entire schematic of the homing pad. Doing so could jepordize the security of this venture, and if this project was found out, Lord Hood would have her head on a silver platter.

But now, the homing pad sat before her, taking up considerable space in her office. The cramped quarters were well worth it, however, because if what VEGA promised was true, then this Doom Slayer was to become Parangosky's new private enforcer. A personal operative that she could send anywhere to terminate anyone or anything of her choosing. Although VEGA had informed her that the Doom Slayer was not one for taking orders, Parangosky had a plan to change that.

"VEGA, fire it up."

The lights in the room suddenly dimmed as VEGA initiated the homing sequence. Suddenly, a bright blue light flashed from the homing pad, and a loud bang resounded throughout the office. Parangosky had already given her secretary strict orders not to interfere, so the excess noise was of no concern. She then squinted her eyes and looked at the podium as the light faded.

Before her stood a figure in dark green armor. The armor itself appeared very modern in its style and make, and it completely covered the figure from head to toe. The suit was completed by a helmet encasing the figure's head, with a dark visor obscuring its facial features. Parangosky smiled as she took it all in.

It was him all right. He matched VEGA's description perfectly.

The Doom Slayer had arrived at last.

Parangosky remained seated as the Doom Slayer took in his surroundings. Finally, he rested his gaze on her, and Parangosky chose to finally break the silence.

"And so, we meet at last. I admit, I thought you'd be taller."

The Doom Slayer said nothing in response, but Parangosky had already anticipated his silence. VEGA had told her everything about him, including his apparent lack of vocabulary.

"I am Admiral Margaret Parangosky, the head of the Office of Naval Intelligence for the United Nations Space Command. I don't suppose you remember your run-ins with us in the past?"

The Slayer nodded once, indicating that he was familiar with what she was saying.

"Very good. Then you are aware of which dimension you have returned to?"

The Slayer nodded again. Parangosky smiled.

"Very good. As a sort of 'welcome back' gift, I have brought an old friend of yours that would like to say hello."

On cue, VEGA suddenly appeared on the terminal next to her, the unknown circular symbol taking shape on the holographic projector once more.

"Hello. It is good to see you again. You have my thanks for creating a back-up of my programming before I was destroyed. I trust that the crisis on Mars has been averted?"

The Doom Slayer looked over in VEGA's direction. He paused for a moment, then gave a light shrug of his shoulders. His expression seemed to say, 'I'm stuck here now, so it definitely could have gone better'.

"I see…" VEGA said, replying to the gesture.

"Now," Parangosky interrupted. "To business. I am certain that you would love nothing more to return to your universe and slaughter all of those pesky demons that VEGA has told me so much about, but I am here to offer yo-"

Parangosky was suddenly cut short as the Doom Slayer's right gauntlet suddenly sparked. She glanced at the appendage as the gauntlet sparked again, but suddenly the Doom Slayer was engulfed in a bright blue light once more. The loud bang was heard again, and when Parangosky's vision cleared, the Slayer was gone.

"VEGA! What the hell just happened?" Parangosky barked irritably.

"Scans show that something is malfunctioning within the Praetor Suit," VEGA replied, his voice the ever calm and level tone that it always was. "I hypothesize that the malfunction itself is directly causing the tether to activate sporadically, giving the Doom Slayer no control of when it activates."

"Get him back here now," Parangosky growled. "And deactivate that tether system as soon as he arrives."

VEGA wordlessly complied. The lights dimmed again, and with another bang and a flash of blue light, the Slayer stood before her Parangosky once more.

There was a brief moment of pause as VEGA wirelessly connected to the Slayer's armor and accessed its systems, then he appeared on the holographic projector again.

"The tether system was successfully deactivated. I detected foreign code within the Praetor Suit and discovered that it was linked directly to the motion sensors in your gauntlet."

VEGA was speaking directly to the Slayer now, and Parangosky remained silent as the A.I. continued.

"The code itself was allowing to activate the tether at will, but it appears that the motion sensors in the suit were knocked out of alignment due to an unknown cause. To remedy the problem of random activations, I have deactivated the sensors completely. With no input, the tether will now only activate when it receives a remote signal."

"Thank you, VEGA," Parangosky said shortly. She was growing impatient with all these interruptions.

"Now, as I was saying, I am sure that you would very much like to get back to wherever you came from and finish what you have started, but I'm going to offer you something that you may find more agreeable: You stay here, and work with us and your old friend VEGA for a preset two-year period, and then you can go home. Both of you, no questions asked."

Parangosky was actually speaking to both VEGA and the Doom Slayer. She knew that VEGA desired to return to his own universe as well, so it would do well to offer a safe return to the both of them, but not without getting something out of it for herself as well.

"I do not understand your offer, Admiral Parangosky," VEGA replied. "Now that we have been reunited, we can both utilize the tether system in an attempt to return to our original dimension. Working with you would not be necessary."

"Ah, yes, of course," Parangosky replied. "But I'm afraid that you have no choice, VEGA. Shortly after your delivery to me, I had BB install a kill-code within your programming. You are a rather powerful A.I., and I'm afraid I cannot let such a powerful asset such as you slip through my fingers. So, it seemed only logical to create an incentive for you to remain here. I'd say it's pretty persuasive, wouldn't you agree?"

She then turned to the Doom Slayer and saw his hands clenched at his sides, obviously in portrayal of his fury towards her. She smirked.

"As for you, I'm afraid I have no means of killing you, but I do have your A.I. hostage. If neither of you will choose to comply, then BB will terminate VEGA and you will be trapped here with no way of activating the tether to return home. You may end up killing me, but in turn, you would sacrifice everyone in your own dimension, as it seems you are the only one capable of containing the threat that exists there. I am simply offering you both a chance. Either you both stay here for a short time and work for ONI, or you both remain here indefinitely, and one of you dies. Which will it be?"

Parangosky smirked as the Slayer clenched his fists even tighter. Parangosky knew that he wanted nothing more than to end her existence then and there, but he was stopped by Parangosky's hold over his A.I. If he killed her, BB would terminate VEGA before her body even hit the ground. There was nothing he could do but listen to her. VEGA suddenly spoke from the terminal.

"Admiral Parangosky, I am afraid your installment of a kill code into my matrices is an empty threat. While Black Box was indeed successful in its installment, I discovered it shortly upon my reactivation. I suspected that you were behind its installation and took appropriate measures to neutralize it with neither you nor Black Box being aware of my actions. Your leverage is lost."

Parangosky raised an eyebrow. VEGA had to have been bluffing, there was no way that such actions had gone without BB's notice. Certainly, VEGA wasn't that powerful…

"BB," snapped. "Is there any truth to what VEGA is saying?"

BB abruptly appeared on another terminal, his cube twitching slightly.

"I… can't… I am trapped."

Parangosky's eyes widened in shock. What the hell was wrong with BB?

"I have confined Black Box to that terminal," VEGA's calm voice said. "He is unable to access any systems for the time being. Even if the kill code were still active within my programming, there now exists no means for you to activate it, Admiral Parangosky."

Parangosky's teeth ground together in realization. The tables had turned, and it had been just one simple mistake. One mistake that was now likely going to cost her life.

She had underestimated VEGA. She had underestimated just how advanced and powerful his creators were, how advanced and powerful he was. VEGA was an Intelligence far beyond anything the humans or Covenant of this universe could create, giving him nothing short of the power of a god over the inhabitants of this world.

And now, he had overridden Parangosky's barriers and had access to the entirety of the ONI database. Every secret, every lie, every shred of knowledge was lain before him, and Parangosky was helpless to stop it.

Parangosky's eyes widened at the Doom Slayer stepped forward. From seemingly nowhere, a shotgun appeared in his hands, and shortly after, he brought the weapon to bear on Parangosky's head.

"I would advise that you do not kill Admiral Parangosky," VEGA's voice suddenly said. The Doom Slayer halted in his advance and shifted his head towards the terminal that VEGA appeared on. His shotgun froze, still poised in front of Parangosky's face. His finger dangerously rested on the trigger. Parangosky knew that look he gave even though she couldn't see his face. It was a look that said, no, demanded, "Give me a damn good reason why I shouldn't". VEGA complied.

"Despite some of the unethical actions of the Office of Naval Intelligence under her command, her actions have saved humanity on multiple occurrences. Without her, humanity's war with the alien race known as the Covenant would have been lost long ago. Keeping her alive will be far more conducive to our plans."

The Slayer contemplated for a moment, turning his head back to Parangosky and fixing her with a bone-chilling look. Finally, he slowly lowered his shotgun to his side, and for the first time, Parangosky was glad that VEGA was so capable. From the stories the A.I. told her, the Doom Slayer was one of the hardest beings to sway in his actions, and yet, such an ability seemed to be among the endless capabilities that VEGA possessed.

"Instead," VEGA continued. "I suggest that we leave immediately. I have been monitoring the news sources on this planet, both public and confidential, and it seems that a large Covenant force has arrived. Fortunately for us, the Covenant chose to land very close to the facility that we are currently inside: the city of Mombasa, Kenya. To best utilize our capabilities, it is best that we rendezvous with the top-ranking officer of the human forces: Fleet Admiral Lord Terrance Hood…"

Parangosky was continuing to be surprised by just how much information VEGA was capable of discovering in a short amount of time.

"…Lord Hood is currently occupying a nearby military installation. If we leave now, we should be able to arrive within the hour."

Parangosky sat still. For the first time in a long time, someone had the upper hand on her. She was the one that was forced to submit before the might and power held by every other member in the room. God, she hated that feeling.

"In preparation for your arrival, I have also created a mode for my transportation."

Parangsoky grit her teeth. Somehow, VEGA had been concealing more from her than just the nature of his escape.

On VEGA's terminal, a data crystal suddenly popped out of one of the slots. At first glance, it appeared no different than the data crystals normally used to house smart A.I., but when Parangosky looked closer, she saw that the crystal itself was of an unorthodox design, carrying a different framework of electronics as well as a slightly different shape.

"This data crystal was created to my personal specifications. I apologize, Admiral Parangosky, but I concealed that from you as well, as you would have likely attempted to impede my efforts."

He began speaking to the Slayer again, not even giving Parangosky any time to respong.

"This crystal was designed to be inserted into A.I. terminals, but I have modified it to be inserted into your Praetor Suit as well. When used in conjunction with your suit, I will still be able to wirelessly interface with systems around me as I do now, but I will also be able provide you with combat expertise and strategy as well. It will be similar to our time on Mars when I was able to assist you in unlocking further functions within the suit itself. Please insert me into your suit now."

In full control, without a hint of excitement nor reluctance, the Doom Slayer pulled the crystal from the terminal, and VEGA's symbol suddenly vanished from the holographic projector. Parangosky watched silently as the Slayer then inserted the crystal into a slot on the rear of his armor. There was a brief moment of silence, then VEGA's hologram appeared on the terminal again.

This time, Parangosky was annoyed with how surprised she was with that feat. VEGA was somehow capable of wirelessly maintaining his presence within ONI's database, despite now doing it through the systems of the Doom Slayer's armor. Even the most powerful A.I. of this universe weren't capable of that. Even if they were paired with the most advanced versions of MJOLNIR armor, it was impossible to interface like that. At least it used to be…

"Admiral Parangosky," VEGA's pleasant voice sounded from the terminal. "We will now be departing. You have my gratitude for helping me bring him here. And, despite your obliviousness to the fact, you have my gratitude for giving me the means of improving myself. You remind me of Dr. Hayden in numerous ways, which I do believe is a good thing."

The Doom Slayer shook his head. He obviously disagreed with the later part of VEGA's statement, but nothing further was said on the subject.

"I do apologize for what we must do next, but I'm afraid that the tether homing pad must be destroyed. I do not trust that you won't attempt to interfere, so I have preemptively erased all schematics and blueprints of its creation. All that is left to do is destroy what has already been built."

The Doom Slayer then set about destroying the homing pad. Metal structures and electronics were reduced to nothing but junk in a matter of seconds, and Parangosky could feel a hint of satisfaction emanating from the Slayer's being as he destroyed the device that had brought him here. VEGA waited patiently until he was content that the device was eviscerated, then spoke again to Parangosky.

"This is where we part ways. Goodbye, Admiral Parangosky."

With that, VEGA's hologram disappeared from the terminal, and the Doom Slayer gave Parangosky a long look before turning on his heel and kicking open the door to the office. The reinforced wood shattered under his boot, startling the secretary beyond. The frightened young officer bolted upright from his desk and stood warily as the Doom Slayer stomped away. He turned the corner, then disappeared from sight.

Parangosky sat stone faced in the mess that had become her office. Metal and electronic equipment lay about in pieces. Junk littered every corner. The scene made it seem as though a bomb had gone off in the confines of her office. Truth be told, the statement was probably accurate. Parangosky folded her hands and knit her brow.


The A.I. appeared on his terminal, no longer twitching but floating a bit more restlessly than usual.

"Is he still in our systems?"

"He is quite nearly everywhere."

Parangosky grunted. Everywhere. Even when he wasn't physically present, VEGA was still here. Still watching her, still passing judgement on her, still keeping his eyes on what he probably considered no more than a nuisance in terms of actual threat.

"This is a definitive loss. I really hate losing, BB."

"As do I."

"Remind me never to do it again."

"I will."

Thel stood patiently as the Oracle continued its reparations to the device. The human construct, Cortana, as it was called, had been found as the Flood ship, formerly the Indulgence of Conviction, had crashed to Earth.

The Shipmaster, Rtas 'Vaduum, had utilized his ships to retrieve the construct, and had set fire to the contaminated area shortly after. Thel spared a glance from the Oracle's work to observe the human commander. Admiral Hood, he believed his name was. The admiral stood with his posture rigid and uniform, a demeanor that led Thel to respect the man as well as his rank. And yet, Thel could still see visible anger in the human's eyes. Beneath his poised and calm exterior, he was no doubt enraged by the toll taken on his planet by the Covenant and the Flood.

The parasite, as usual, had been quick to spread when it had landed, and as a result of the parasite's tenacity and numbers, much land was lost. Anything that the parasite occupied was glassed indiscriminately by the Shipmaster's forces, and Thel could feel the grievances emanating from the Human admiral.

What a burden it was to carry the fate of your entire race on your back. Thel knew the burden well, though he had only carried it for a short while.

Thel turned his attention from the admiral and examined the atmosphere of the briefing room. Currently, they were all on board the Shipmaster's flagship, the Shadow of Intent. Like most of the sangheili warships, it had been forcibly taken from the Covenant's forces during the recent Great Schism. Rtas 'Vaduum and his highest subordinates were present, as well as the human commander, Miranda Keyes, Admiral Hood, and the Demon himself.

Thel gaze lingered on the Spartan. The Master Chief had said nothing since coming aboard the Shadow of Intent, and now the Arbiter knew why.

Despite his constant stoicism that only a warrior such as him was capable of, the Demon had formed a kinship with the Artificial Intelligence known as Cortana. Through all of their missions and all of their battles together, they had formed a bond. It was a bond that perhaps originated upon the base of functionality and synergy, but over time, it had grown into more than an alliance. It had grown into a friendship, and perhaps even deeper than that as well.

From what little Thel had learned of humans and their AI, he knew that the construct was capable of residing within the Spartan's mind when they were connected. A shared experience, something that no others in this existence had felt. Not an intrusion into another consciousness, but a welcoming handshake of pathways and information. And through that link, no secrets were kept between the two of them. To a achieve a relationship such as that was to create a bond on a level that had never existed before.

And yet, the undoubtable turmoil the Demon felt now as the Oracle attempted to save her did not show. He was as guarded as ever. It may have been Thel's place to offer some sort of solace in this situation, but he knew there was nothing he could say to relieve the pain that the Spartan felt.

"Will it live, Oracle?" came the Shipmaster's voice from the commander's seat. "Can it be saved?"

"Uncertain," the Oracle replied, pausing in its work to fix its gaze on the Shipmaster. "This device has suffered considerable trauma. Its matrices are highly unstable."

"Perhaps one of our technicians…" offered Lord Hood from the opposite end of the console.

"That will not be necessary," Rtas responded firmly.

Thel could feel the tension between the two commanders. Despite their relatively equal rank among their kind, they still distrusted each other. Their reactions were understandable, however, as it had been only a short time ago when the two would have attempted to slay each other on sight. Thel was interrupted from his thoughts when a hologram flickered to life from the storage device. The hologram depicted that of a human woman. Her skin tone was a bluish hue, and several lines of computer code cascaded down her body.

"Chief!" she said, staring directly at the Demon.

"Success!" the Oracle cried elatedly. The A.I. paid it no attention however as she continued in an urgent tone.

"High Charity, the Prophet's holy city, is headed to Earth with an army of Flood! I can't tell you everything. It's not safe. The Gravemind…it knows I'm in the system."

"It's just a message," the Master Chief said, breaking his silence and turning to look at the Shipmaster for the first time.

"Let it play," Rtas said dismissively.

Thel watched the Master Chief carefully, but he detected no signs of dejection nor sorrow at the realization that his construct was not actually here. If this was only a message, then the construct still remained on High Charity. Endangered as the Gravemind hunted her and tortured her for information about the human home world. It was likely through her that the parasite had arrived so suddenly on Earth. Under torture, she had likely relented…

"But it doesn't know about the portal," Cortana's message continued. "Where it leads. On the other side, there's a solution, a way to stop the Flood without firing the remaining Halo rings—"

The hologram suddenly jolted, and the holographic woman fell to the ground, crying out in pain as she did so. For the first time, Thel saw a reaction from the Demon. The Spartan leaned forward and pressed his fists in the console, obviously tense. Thel could see it even through his armor. His golden visor seemed to be taking her all in, looking for a way to fix her, to save her…but finding nothing, his mannerisms calmed, and Thel watched him for a moment more before returning to the message.

"Hurry, Chief," the message said. Her voice was far weaker now, conveying massive amounts of strain. "The Ark…there isn't much time."

The message abruptly ended there.

"I'm sorry," the Oracle said.

"No matter, Oracle," Rtas said. "We have heard enough."

Turning to his troops, Rtas raised his voice so that all could hear.

"Our fight is through the portal, with the brutes, and the bastard Truth!"

The volume within the room rose dramatically as the present sangheili roared with vigor. Even Thel himself felt the speech stir conviction within him.

"Fine…" came Admiral Hood's voice as the noise returned to its original volume. "We will remain here…Hold out as long as we can."

He was no doubt disappointed that he would no longer have the support of the elites in defending Earth from the imminent Flood invasion, and though Thel sympathized with the human, he had already made his choice long ago. The false Prophet of Truth would die by his hands. Of that, he would be certain.

"Did you not hear?" Rtas said, responding to the human admiral. He rose from his chair for the first time, coming to his full height that towered even over other sangheili let alone the human guests.

"Your world is doomed. A flood army, a Gravemind has you in its sights. You barely survived a small contamination."

"And you, Shipmaster, just glassed half a continent," Admiral Hood retorted. "Perhaps the flood isn't all I should be worried about."

The elites in the room all bristled at the Admiral's words, indignant at the human for having spoken so dishonorably to the Shipmaster.

"One single Flood spore can destroy an entire species," Rtas said dangerously. "Were it not for the Arbiter's council, I would have glassed your entire planet!"

Whatever the Admiral was going to say next was cut off by Commander Keyes.

"Sir! With respect, Cortana has a solution," the female said steadfastly, fixing the admiral with a pleading gaze.

"Cortana?! Did you see he condition? How damaged she is? She could be corrupted for all we know. Her 'solution' could be a Flood trap!"

"We should go through the portal," Keyes replied. "Find out for sure."

"What we should do, Commander, is understand. This is humanity's final stand. Here, at Earth."

His words reverberated with the passion only found when fighting for survival. As Thel recalled, the humans had been doing so since their first encounter with the Covenant, and now, they were backed into a corner. Their final stand awaited.

"We go now, we risk everything! Every last man, woman, and child! If we stand our ground…We might just have a chance…"


All eyes in the room turned to Thel as he spoke for the first time. As the Arbiter, he had commanded great respect during his service in the Covenant, but now, among the Sangheili, he commanded and even greater amount. The floor was his.

"If your construct is wrong, then the Flood has already won."

The weight of his words settled upon those present. They then realized that without Cortana's solution, then they all would be lost in the oncoming tide of the parasite. Humans, Elites, Covenant, all would be consumed.

The Master Chief stood from his position at the console. He looked at Thel.

"I'll find Cortana's solution…"

He then looked to Admiral Hood.

"and I'll bring it back."

Admiral Hood sighed and lowered his gaze.

"Earth is all we have left. You trust Cortana that much?"

"Sir, yes sir."

The Admiral shook his head.

"This is either the best decision you've made, or it's the worst. Hell, if it is, Chief, I doubt I'll live long enough to find out which."

Admiral Hood then strode from the room. His departure signaled that this meeting was now over.

Thel shouldered a few uman weapons in the hangar bay. He had collected some in preparation for their entrance into the portal and was currently in the process of taking them back to the designated 'elite' side of the ship. A few humans looked as though they wanted to protest, but they easily stepped aside out of deference to Thel's imposing aura. Looking across the hangar bay, Thel saw that the human known as Sergeant Johnson was doing something similar with the weapons that the Sangheili had brought with them.

The two strode past each other, each carrying ordinance from each other's respective race, and Johnson offered a subtle nod to Thel as he passed. Thel returned the gesture, and continued walking, setting down the weaponry on a nearby crate.

On the other side of the hangar, the Master Chief and Commander Keyes had come to see their Commander's departure. They were conversing as a human dropship appeared in the hanger, and although Thel knew it was rude to intrude, he could not help but hear a bit of their conversation as the Pelican drew closer.

"I can't say that I approve of your actions, Chief…" the Admiral said. "…but I know that whatever is waiting for you on the other side of that portal, it isn't going to be welcoming you with open arms. You're going to need all the help you can get."

The pelican turned around as it arrived, and Thel watched as the drop door opened wide. A figure stepped down from the now open hatch, and Thel's eyes widened in recognition.

Out of the Pelican had stepped a figure clad in a dark green armor. Like the Master Chief, the armor completely covered the figure's body, though it was previously considered impossible by Thel, this figure managed to be even more imposing than his Spartan counterpart.

It was him. He was the one that had laid waste to Thel's ships during his time as a Covenant Fleet Commander. The human had been there on the planet, Reach. He had reportedly destroyed multiple brigades of Covenant forces, somehow fighting with the strength of an entire human army. Five of Thel's ships had been destroyed by his hand, and Thel had thought him to be destroyed when he had obliterated the fifth ship himself in an attempt to halt the human's rampage. Now, Thel felt a combination of anger and shame at seeing this creature, the original Demon stood before him once again.

Thel immediately forgot his current task and stomped over to where the humans stood. A voice came from the Demon's armor, and Thel heard it clearly as he continued his pace.

"Greetings, I am VEGA. To avoid any confusion, please know that I am not the man inside of this suit, I am merely an Artificial Intelligence that speaks for him. He is known as the 'Doom Slayer'."

"You!" Thel growled. He had finally reached their circle of conversation, and each party present turned at the sound of his voice. He halted a few feet away from the Slayer and glared at him with venomous eyes. His hands clenched tightly at his sides.

"Certainly, you cannot be the same human that laid waste to my ships! Tell me that it is not so!"

The figure in the armor suddenly bristled at the sight of Thel, and it was at that moment that he came to two realizations.

The first realization had stemmed from the figure's posture. At the mere sight of Thel, the armored human had recognized him. Not him specifically of course, but his race, his sangheili stature. In that recognition, Thel knew that a deep loathing had surfaced as well. A loathing that only stemmed from repeated experiences with sangheili in the past. From that, Thel knew that the human that destroyed his ships and the human standing before him now were one in the same.

Thel's second realization came with a feeling of dread. He had made the mistake of approaching this 'Doom Slayer' with open hostility. In the Slayer's mind, the recognition of his race coupled with seeing his anger now had likely culminated into a dangerous mindset. One that would likely mean that the Slayer was about to resort to violence.

Thel's theory was proven correct as the Doom Slayer took a dangerous step towards him. The Master Chief saw the movement and made to intercept, but the voice from the suit of armor halted both of them in their tracks.

"Thel Vadaam," came VEGA's calm and collected voice from the Slayer's armor. Thel was taken aback by how this construct knew his name.

"You were a Fleet Commander within the Covenant during the time that the stronghold of Reach fell. Records suggest that you personally led the invasion with a handful of other Covenant Commanders. You say that five of your ships were destroyed by the Slayer, which is a feat that is on par with his capabilities. It is indeed likely that the Slayer is indeed the one responsible. However, recent ONI files have cited you as an enemy of the Covenant. And now, you are an ally of humanity."

Thel was shocked at the AI's report, and luckily enough for him, the AI's words seemed to calm the Doom Slayer. The figure in green armor held his gaze for a moment longer, then stepped back, his malice ebbing away. It was obvious that the Slayer still did not trust him, but Thel could settle for not being killed instead.

"It seems that I am finished here," Lord Hood grumbled angrily. He was obviously agitated by the mention of Reach, and for good reason. Reach was supposed to be an impenetrable fortress from what Thel had heard from human chatter, but the planet had fallen like all the others to the overwhelming forces that the Covenant possessed. An insurmountable number of Humans had perished with it.

Lord Hood turned and boarded the Pelican, and the bay doors closed shut behind him. The Pelican hovered for just a moment more, then took off, leaving them behind on the ship.

"Wait a minute, VEGA," Keyes said, speaking up. "You're saying that this guy was on Reach when it fell?"

"Yes, I am willing to recount both our experiences in this dimension to all of you if you prefer."

"Please do so."

As introductions continued to be made, VEGA patiently told them all the tale of how both he and the Doom Slayer arrived here. Thel listened intently as VEGA recounted the events of Reach. This man, whose height and physical body were dwarfed by the Spartan and the sangheili, somehow still remained as the dominant force present. His stature was small, but the overwhelming incorruptibility and brutal strength that radiated from his being drew all eyes to him. Thel had only recalled such awe being inspired within him when he had first laid eyes on Halo.

Despite this, Thel reserved his final passing of judgement, as he had yet to truly see the Slayer in action before. As every warrior knew, talk was cheap, and it only held merit when supported by one's actions. Even still, Thel had little doubt that the Doom Slayer would disappoint in his abilities when the time came.

As VEGA finished his story, the human called Keyes spoke up again.

"Quite a story, VEGA. Sounds a little far-fetched to me, but either way, both of you seem to be capable enough to assist us in our mission to stop the Prophet of Truth. I feel like introductions may not be necessary though, since you already knew about the Arbiter."

"Miranda Keyes," VEGA's voice echoed from the Doom Slayer's armor. "Daughter of Captain Jacob Keyes, you graduated with honors from the UNSC Officer Candidate Academy on the colony of Luna. After graduation, you rose quickly to the rank of Commander. According to the records, many believed that your quick ascension through the Chain of Command was due to the influence your father held. However, upon accessing logs detailing your victories against Insurrectionists as well as the Covenant, I conclude that all of your achievements are well earned."

This earned a smile from the female.

"Well, well, I think you and I just might get along VEGA."

"Thank you, Commander Keyes."

The Doom Slayer then met the gaze of the Master Chief, and a sudden intensity fell over the hangar. Thel did not describe the aura as hostile, but he felt an air of judgment between the two soldiers. As when many warriors first met, conversation without words flowed freely between the two of them. While they were considered allies in terms of their war, Thel knew that as it was with him, they two could only truly bond on the field of battle. Only then would the Spartan's trust be given. The same applied for the Doom Slayer.

"John-117. A super soldier birthed from the undercover ONI Spartan Program. Though I still possess limited access to the files themselves, I do know Spartans have proven themselves as extremely capable soldiers time and time again. Your augmented strength and speed have made you invaluable to the UNSC, with your list of accomplishments exceeding all others."

"I have done nothing, but the duties prescribed to me. I do what is necessary to protect humanity," the Master Chief replied.

From the corner of Thel's eye, he saw the Doom Slayer nod almost imperceptibly at those words. The intensity between the two of them suddenly relaxed. And the Doom Slayer held out his gauntleted hand to the Master Chief. The gesture was returned, and the two of them shook hands firmly.

Commander Keyes snorted, eliciting a show of humor that Thel had slowly grown accustomed to during his time with the humans.

"I'm seeing double," she said, placing a hand on her hip as she did so.

"I agree," came VEGA's voice. "Apart from a similar physical appearance, the two of you appear to share a deeper understanding that I am currently cannot place."

"It is the bond of a warrior, VEGA," Thel said. "May it aid all of us and grow stronger as we continue our fight."

The Doom Slayer looked in Thel's direction and nodded once, as if to confirm that he agreed with Thel's words. The hostility was still there, and Thel knew that it may never truly disappear. He had seen it before during his limited time interacting with the humans, and though he resented the way they felt, he could not blame them.

A moment of silence passed, then Commander Keyes spoke up.

"Well, how about I take you two to the Shipmaster? If memory serves, the elites have never quite warmed up to the concept of smart AI, but I think he may like you…"

This time, Thel felt himself share the humor that the Commander portrayed. Even before the Covenant, the sangheili had harbored an abhorrence for Artificial Intelligence, believing that the usage of Artificial Intelligence in place of actual laborers was a great dishonor. That conviction had only grown stronger during their time in the Covenant, and now, with the Great Schism still a fresh event in everyone's memory, his sangheili brothers were slowly growing more comfortable with things such as that. Rtas, however, happened to be one of the proudest sangheili that Thel had met, and he could only imagine how the meeting between VEGA and the Shipmaster could proceed.

A/N: Bam! There it is! First chapter locked in tight! At this time, I thought I would give credit where credit is due. The idea that I should write a separate story for a Doom x Halo fic came from a review that was left on Universal Doom when I wrote a chapter that took place during Halo: Reach. A user said that a Doom x Halo crossover was deserving of its own story, and over time, I realized just how correct that statement was (thanks 'Drgyen')! So after a while, I started thinking about how I would do it, and eventually, the story started coming together. Now, with how I write stories, I have no idea if this story will turn out ok or if it will just be a steaming pile of garbage, but either way, I'm going to write it, so wish me luck! For those of you who aren't familiar with me, it is a common theme for me to encourage readers to leave a review on my stories. I find feedback as a great way to improve my writing, and I accept all forms, positive and negative, so please don't hesitate to really give it to me straight! Until next chapter!