This is based on the Japanese version of the anime with a few exceptions. See Author's Notes for details.
This is yaoi.
The usual disclaimers apply.
Seto strode purposefully toward his cabin, Mokuba straining to keep up behind him while lugging his case of cards. He did not stop until he was safely within, stationed decisively at the porthole. Unfortunately, the porthole was not conveniently positioned for Seto's height, so he had to look down to see out of it, but he was not going to compromise, and he wasn't really interested in looking out across the Nile anyway. If he had been, he would have been on the deck at the rail, but he wanted privacy and that could only be obtained here, in their cabin.
"Nii-sama? … Seto? Are you OK?"
Seto didn't bother replying to his brother's query. Mokuba was used to his brother's moodiness and would cope with it. He would make it up to him later on.
But now …
He had his own coping to do.
This ceremony, this duel … it was … all to send him …
… to the afterlife.
Just thinking about it made his head ache. He'd worked so hard to ignore all this supernatural absurdity, compartmentalize it, and here it was, shoved in his face. Again. And … Yugi … no, not Yugi … he was … what? A spirit? A ghost? A piece of that puzzle around Yugi's neck? It made no sense.
His rival … the only one he could call his equal … was …
How could he be no more than a mere wisp of electromagnetic energy? A concept? A dream?
But … worse than that, how could he even consider walking out like this? He thought that … monster … was it? Did he not even understand who his true adversary was? His rival? How could he? After all they'd been through …
How could he just … surrender?
He felt it, like a vice, around his heart. He folded his arms over his chest in his typical posture, but he felt as though he were trying to protect his chest from further injury.
It wasn't helping.
Mokuba had placed Seto's case carefully on the desk in their cabin and had now climbed onto the bunk next to Seto. Without a word, he leaned against his brother, linking his hands around his neck silently and placing his head on his shoulder, bewildered, but trying to comfort him as best he could. Seto was only dimly aware of Mokuba's efforts as his mind continued to churn.
Yugi—Seto shook his head: the other Yugi—was so focused on the past and yet … their past, here, now—meant nothing? How could he, Kaiba Seto, his rival—his top rival, mean … so very little? He couldn't comprehend it.
Not only that, he required assistance, the aid of a warrior, a duelist and … who does he choose?
The crushing agony Seto was suffering in his chest increased.
That "other self," that's who.
How dare he? After everything … after all that … How dare he choose that upstart, that pipsqueak, to duel him? He was untested! Who the hell had he dueled to earn the right? Yes, this … spirit Yugi … had beaten Seto more than once, but even he had recognized Seto as an equal! Had not he, alone, of all people on the planet, earned this right? Over and above all the others?
If this other Yugi absolutely insisted on departing and he required assistance to do it, then … the least he could do was … the least … was choose …
Seto closed his eyes briefly.
He had earned this.
He wanted to go straight out to Yugi's … he gritted his teeth … their cabin and talk to him … but there was more than a 50% likelihood that he'd run into the Yugi that he wanted nothing more than to throttle. Even if he did meet Yugi's "other self," the chances of having a normal conversation were—he closed his eyes, thinking about it—minimal. He tightened his crossed arms as though to bar his own passage.
And then there was the—he grimaced in disgust—Yugi-tachi. They would be monopolizing him for the entire remaining time. There was no chance of having any privacy for any possible discussion … or …
… Or what?
What did he think would happen if he met with the spirit now?
Seto was a little afraid to find out. He didn't dare to follow the tangled threads of thought that trailed down into the lower depths of his consciousness. There were too many surging and dangerous … emotions … threatening there.
He sighed. When had he ever had the opportunity to actually have a real conversation with the spirit? What would happen if he tried? The circumstances filled him with confusion and regret. If he attempted to talk to the spirit now, he feared what would come out as a result … what he might … do.
But more than that … there was something … something that seemed to come to him from deep inside, from a place he didn't recognize, a place so deep and secret that it almost frightened him. A voice …
… his own voice, filled with a passionate yearning …
I've waited so very long …
This was the last office I could perform for you, and you—
Why, my Pharaoh?
It was only when he heard Mokuba's concerned query that Seto realized that he had uttered a faint moan at the sudden pang of grief that flooded his body. It was all that he could do to remain standing.
"I'm quite all right, Mokuba," he said, recovering himself. What was that?
"That didn't sound all right."
"Nii-sama, do—do you want me to leave?"
"No, Mokuba. I'm glad you're here."
They stood as they were for some time.
I am currently posting a 5D's story, but I thought I'd post this as a preview. The prologue turned out to be a little static I think, but I found it unavoidable & it's at least short. I apologize in advance if it turns out that I don't update as frequently as I'd like, but starting this will give me incentive to finish the story.
Japanese version: Because the American (4Kids) version changed things/characters around quite a bit.
Yugi-verse notes (spoilers, natch):
~ Seto and Yami Yugi first meet via the theft of the card, followed by the penalty game, Experience of Death (manga).
~ The Experience of Death inspires Seto to create solid vision technology (good) and Death-T (not so much). This leads to the second duel and Seto's second penalty game, Mind Crush (manga).
~ The mind crush results in a period of catatonia (manga) rather than introspection (anime (Seriously?)).
~ However, anime basis means that anime-only arcs (Noah, Atlantis, etc) occurred.
~ As to the duel between Atem and Yugi: Obviously, for this story to proceed, something has to have changed from canon. See the notes for the next chapter.