AN: I don't own Danmachi, Fate or whatever series appears here. The only semblance with the Project X Zone games is the multicrossover aspect and couldn't think of a much better title.

Orario. The Labyrinth City.

Home of the legendary Dungeon, cradle of monsters, which was sealed 1000 years ago by the Gods who descended upon the mortal world, that was when the city was first founded, beginning with the Tower of Babel.

Nowadays, it houses Adventurers, who, blessed with the Falna of the Gods, gain the strength necessary to challenge its depths and slay the monsters. All that for power, riches or fame among other things.

However, before all that, preceding the Age of Adventurers and Gods, the mortal races were at the mercy of the Dungeon's malice, whose monsters raised death and destruction upon everyone.

For that reason, mortals reached out towards the Spirits, the most beloved children of the gods, and made contracts with them so that they could use their almighty powers to defend civilization and spread hope. Those were the Heroes, of which uncountable tales were written, which inspired generations upon generations of Adventurers to follow their steps and create their own legends.

Alas, the need of Heroes was diminishing, and with that, the Spirit contracts fell into disuse, not helped by many of the strongest Spirits disappearing or laying low.

But now? Now was the time for a new Hero to rise, the Last Hero to ever appear. And for that, he will also make contracts with the Spirits.

However, those are not the same contracts as old, neither are these Spirits the same as everyone in that world knows them.

In a region outside time and space, exists an archive known as the Throne of Heroes. This spiritual library records the souls and legends of Heroes as well as Anti-Heroes from every world imaginable. Those "Heroic Spirits" would then wait to be summoned for the defense of their world or as Servants, fragments of their greater selves which usually participate in battle royales for the omnipotent wish-granting artifact known as the Holy Grail.

Usually, being the keyword.

Rejoice! For these mighty Heroic Spirits will lend their wisdom and strength for the newest and latest Hero, so that he might walk with pride and humility this new future for Adventurers, Gods and even Monsters!

For the very best of the omniverse will make all of Orario, nay, all that world to be witness of their prowess and demonstrate why they were known as Heroes of their own realms!

Project X Familia

"So that's the place." A black coated individual, with the hood covering his face, was observing the city of Orario from a distance.

"I admit, those previous worldlines were… interesting and still full of potential." The man mused. "However… I feel that a little more of 'crossover' should be necessary for that variation of the Servant System to reach the maximum of the possibilities."

Even with his face hidden, his excitement was very palpable "Well! Time to begin the experiment! First, find the boy and bring him the package. Piece of cake! Even I cannot believe how trusting he is at this moment in time."

The man opened a dark portal and went inside it.

Project X Familia

Bell Cranel, a 14-year old albino Adventurer, was traversing the streets of Orario after a productive day in the Dungeon.

He has to pass all days there if he wants to gain money to support his Familia. The Hestia Familia, of which he is the only member, is extremely poor. While they don't live in the streets, their only home is a decrepit church, and that one was property of a friend of Hestia that took pity on her. The little Goddess even has to take multiple jobs to sustain themselves and they often eat from leftovers of her food selling stand.

That was one of the reasons he wants to become stronger: monsters of lower floors contain magic stones of greater value, however, his stats are not enough to take them on without dying or being maimed, despite the ridiculous growth he's being experiencing.

The other reason… well, let's just say he had a crush on Ais Wallenstein, a high-ranking Adventurer from the prestigious and powerful Loki Familia, the Sword Princess. However, to be able to at least have a chance with her, he needed to become stronger, as much or more than her. Which was easier said than done. She was Level 5 while he was a measly Level 1.

… and maybe, possibly, be like those Heroes of old that he and his grandfather admired so much.

"Well, maybe you can be one soon."

Bell yelped. A few pedestrians watched him weird but quickly ignored him. What was that? Did someone talk to him?

"No, I was talking with this hot chick. Of course I was talking to you!"

… and can apparently read his thoughts. Was he turning crazy?!

"*Sigh* Just look to your left. And yes I was reading your mind."

Bell just looked towards his left and blinked. At the entrance of a backstreet, there was a person with black clothes, from the gloves, to the shoes, even the longcoat and the pants were the same tone of dark. And he, the figure looked like a man, was looking at him. Heck, he could even feel his gaze from that distance. Somehow, there was a subtle feeling of pressure coming from that guy, which made his instincts flare in alert, just like in the Dungeon but more subdued.

The rookie Adventurer observed his surroundings. It seemed that no one except him took notice of the black coated guy. When he turned to him again, the black coated guy was now crossing arms and tapping his foot impatiently.

Gulping, Bell decided to enter the alley, despite not wanting to. He had the feeling that something bad would happen to him if he left.

"Finally." The black coated man exaggeratedly "Do you know what time is it? I have a busy schedule, man!"

"S-sorry." Bell stammered "But a guy reading minds doesn't inspire too much trust."

"Oh." The man simply let out before scratching his head "I was thinking of a mysterious and dramatic approach. Usually, selfless and heroic people go towards the source of unknown telepathic voices without thinking too much about the possibly morally ambiguous callers."

Bell's face reddened "Oh, well, I… wait a minute, were you implying I am an idiot?!"

"No, I just called you naive."

"That's not better!"

"But are you denying it?"

The lack of response from Bell as well as his nervous expression told him everything.

"Anyway, I just couldn't help but take notice but you were lacking in personnel."

Bell sighed "Yeah, I was thinking about that earlier." Curse his very transparent thoughts! Though to his defense, no one would expect a telepath even if the ability was theoretically possible given how the Falna's magic and skill system worked.

"Well, no need to worry anymore for I have a way to solve your little big problem!" He hammily exclaimed like a salesman in a carnival.

Bell blinked "Really?"

The black coated man, without much fanfare, shoved a wrapped up box into Bell. "Here, take it."

"W-what?"

However, during that moment of distraction, the black coated man disappeared. Just like that. Not even a flashy exit. And when Bell returned his gaze to the box, he saw a piece of paper that read "Open at home."

Bell couldn't help but sigh. Just who the heck was that man and why did he want to talk to him? And what could be in the box? So many questions and very little answers. He'll talk about it with his Goddess to see what they should do.

Project X Familia

Apparently his Goddess wasn't home when he arrived.

He already arrived at the church a while ago, so it should be around that hour that Hestia returned home from her job. Unless something happened like an unusual number of clients or her having her own plans for the afternoon. Or maybe someone kidnapped her, like a sack of potatoes, to declare war to all of Orario?!

Hahaha, come on Bell, don't be that ridiculous, he said to himself after the last one. He always did have a large imagination, what with his perverted and hero-obsessed gramps trespassing all his tastes to varying success.

(At least we all know now he didn't inherit that old geezer libido.)

"I wonder what's in that box…"

Bell, without anything better to do, decided to retire the box's wrappings, revealing that it was made from some sort of black material with highly stylized letters engraved in silver at the top.

"Servant Summoning Kit for Dummies."

With his curiosity growing even more, he opened the box, the insides of it containing a sheet of folded paper, a booklet, and most unusual of all: a golden goblet.

The goblet was heavily engraved, beautifully at that. He knew that if it wasn't even made of gold, it would fetch a decent price if sold.

Turning to the booklet, he saw that it had the title "Manual Booklet" and began to read it.

"To the one reading this booklet, congratulations! You are now the proud owner of a Holy Grail and can now use it to summon your own Servants!"

"To clarify on its functions, you must know the story of the Holy Grail Wars. Once upon a time, three mage families: Einzbern, Tohsaka and Makiri (who were later renamed to Matou), built a system designed to reach the Root, a metaphysical location that is said to be the source of all creation, which consisted of using the souls of seven Heroic Spirits to open a hole that leads directly to it."

"Heroic Spirits, as their name indicates, are the souls of individuals that left their mark in history, even to the point of legend, empowered by their own stories for generations. Those Spirits are located in another intangible realm called the Throne of Heroes, separated from the cycle of reincarnation. However, the definition of 'hero' is loose there, for there are also villains and anti-heroes. The impact left to the world is what counts to be registered in the Throne, not altruism."

"Unfortunately, Heroic Spirits are existences akin to Gods so their manifestation is all but impossible for mortals, no matter how powerful the summoner is. So they decided to simply summon 'fragments' of those Spirits and stuff them in temporary familiar vessels known as Servants, which are much more manageable to support despite dwarfing normal humans in strength."

"Even with that, the Holy Grail, the system built by the families, can only be used once, and that's in the form of a wish granted to the one that makes contact with it. So debating about what to use it for degraded into violent infighting because of the disparagingly different interests."

"So the once sacrifice ritual turned into the much more known fight royale, with an increasing number of rules as well as variations."

"This Grail you're holding is a simple bootleg version with only the Summoning function. Wish granting and Root access are not possible with it."

"A piece of warning: supporting of a Servant is exhausting in itself, so three it's the utmost limit a mage can safely maintain without collapsing. However, the Falna allows for the increase of magical reserves, so an Adventurer should be able to have more than three Servants. In fact, the magical stress should translate into an elevated Magic stat so don't be afraid to summon more! Though don't forget that some Servants are more cost expensive than others so be careful."

"Servants are classified into seven classes: Saber, Lancer, Archer, Rider, Caster, Assassin and Berserker. Each with their own self-explanatory abilities though each Heroic Spirit will have unique battle styles and skills, even some that should be outside their respective classes."

"Right here are the procedures and incarnations necessary for the summoning. The Grail already optimizes the process so it shouldn't be too difficult."

"P.S.: There exist Extra classes that shouldn't be possible to summon in a typical Holy Grail War, like Ruler for example. Who knows, maybe you're lucky and the gacha smiles upon you. Just try!"

Bell just could only gap. A wish-granting device? A battle between the souls of past Heroes? And he has the means to summon those same Heroic Spirits?!

This… this was too much. How would he, a country pumpkin from a rather poor and weak Familia, being given something that was too good to be true? It must be a scam…

But, what if it was true? What if he can summon those Spirits? Even if weakened, they're still Heroes, so they should still be much stronger and experienced than he was. And if they wanted, they could become members of his Familia, helping it to become at least strong enough to live without money trouble. The load would at least be lifted from his Goddess so that she wouldn't work herself to exhaustion. And they could possibly teach him to be a better Adventurer and maybe… a Hero.

Taking a leap of faith, he continued to read. It seemed the folded paper had already a drawn Summoning Circle so all he had to do was to put the Grail near it and say the incantation.

He put the Grail at the center of the circle, which in itself was in front of the ruined alter.

Breathing once again to calm the nerves, Bell pointed a hand towards the circle and began to chant:

"Let silver and steel be the essence.

Let stone and the archduke of contracts be the foundation.

Let red be the color I pay tribute to.

Let rise a wall against the wind that shall fall.

Let the four cardinal gates close.

Let the three-forked road from the crown reaching unto the Kingdom rotate."

"Let it be filled. Again. Again. Again. Again.

Let it be filled fivefold for every turn, simply breaking asunder with every filling."

"My will is your body, your sword, my fate."

"I swear to embody all the good of the world.

So Guardian of the Balance, come forth!"

With each line of the chant, every second that passed, Bell felt like something was being drained from him. His nerves were burning, the muscles hurt and his head felt like it was being hammered. Nevertheless, he persevered.

If he couldn't handle this, how will he be able to be at Aiz's side?

With a roar, the circle intensely glowed and made a burst of wind, making Bell fly a few meters back. Though thanks to his Falna, he didn't suffer any contusions.

Heavily panting and a little dizzy from exhaustion and impacting against the ground, he barely observed that the light from the circle has receded. In its place, revealing someone with a black armor of design and materials that he had never seen before, with an 'N7' insignia in the chest. He also had a near shaved head and beard as well as very intense and hard blue eyes.

Bell may not be the brightest social butterfly but he instantly knew, instinctually even, that figure just screams respect as well as a charm that not even high class Adventurers and Gods could find easy to resist.

The man took upon his ruined surroundings, as if wondering why he appeared at decrepit church, though when he looked upon Bell's downed state, his eyes widened and immediately came towards the teenager, offering a hand.

Bell accepted it, consequently being helped to stand up. Gaining his breath, Bell turned towards the man "Thank you."

"Don't worry, Master or not, I would have helped anyway."

"Uh?" Bell blinked "Master?"

The man simply pointed towards the Grail, with Bell being hit with a realization."

"No way…"

The man let out an amused smile "Lieutenant Commander John Shepard of the Alliance Navy and Servant Rider. Are you my Master, no, my Admiral?"

"Uh…" Bell's jaw was dropped "Maybe? Ouch!"

Bell's right hand suddenly felt like on fire, not unlike how he was in the summoning. Quickly putting out his glove, he saw that red marks: two knives standing behind a fire, were now on the back of his hand. Strangely enough, the knives resembled rabbit ears.

"Seems like you are." Shepard simply let out.

As if Bell's day couldn't be full of surprises, a loli boobed Goddess unintentionally took her chance to enter the scene.

"I'm back, Bell!"

AN: After reading Heroic Myth and Grand Dungeon Oratoria, I decided to give harouki's concept the Fate:Zero Sense treatment, so instead of Bell summoning proper Nasuverse Servants, he summons people from different works of fiction.

And I begin this off by summoning Commander "motherfucking" Shepard. He may not be one of the most powerful Heroes out there but he's still very versatile: expert soldier, born leader, shrewd negotiator and one of the finest role models Bell could ask for as a Paragon.

Also, his Noble Phantasm, the Normandy SR-2 (Anti-Fortress) (A), gives him also access to all his weapons and armors as well as his crewmates, which elevated to Servant status, can still give Shepard enough firepower to give even high-ranked Servants trouble as well as demolish a city or two. He would be around a Level 4 or 5 in physical stats, though again, weapons and skills enough to outmaneuver even Level 6.

And yes, I plan on introducing the Extra Classes. While that still would put more characters in the story, that's nothing in comparison to the hundreds of Servants in Grand Order.

As a rule, only one franchise for Servant and no one from the Nasuverse. They're already selected so no recommendations… though I dare you to guess who I will summon and the class.

The franchises that will appear, apart from Mass Effect, are: Jackie Chan Adventures, Megaman Zero, Scissors Seven, God Eater, Sword Art Online, Astral Chain, Kamen Rider Build, Symphogear, Puella Magi Madoka Magica: Magia Record, Prototype, Honkai Impact, Kingdom Hearts, Date A Live, Persona 3.