Disclaimer: I don't own Yugioh. This will make more sense if you've read the Millennium World manga.
"It's your own fault, you fool," the spirit said almost sadly as he watched the thief's fingers crumble slowly to dust. "Your fault, and the fate that dictated this would happen again."
The thief, crying in terror, couldn't hear him. The spirit hovered above his hunched form, arms crossed, master of the game yet forced to sacrifice a pawn. It'd been expected, of course. He'd needed his thief up to this point and now the plan required his involvement no longer. Still, the thief had failed, destined or not. He required punishing.
All this the spirit knew, yet he'd been dogging this thief's steps since discovering him the key figure on his side of the field, fascinated and more than a little bit proud. So this might be who he had been, years ago...? He still couldn't be sure, couldn't know for certain if any of himself had ever belonged to this arrogant, wild, defiant man who'd dared stride into a throne room and declare himself a king. He thought he saw a little of himself in the tilt of the thief's head, every now and then; in the sly smirk that crept across his face, insanity slicing his expression in two; in the way he laughed in the face of adversity and knew himself strong enough for the task. But the thief wasn't laughing now.
The spirit wasn't, either.
"Was it my family who died too?" he asked, wondering whether it mattered - the answer to that question, at least, was "no" - and the thief gave no alternate reply. "Is my revenge yours, or do I just destroy because destruction is what I am?"
The thief was too busy watching his stomach dissolve, so the spirit shrugged, swept in low. Just another sacrifice, and he'd know everything soon enough. Once the god, the god he knew himself to be, returned, there'd be no more of this ridiculous softness over identity. They'd had a good run, this thief and he. But they couldn't fight fate.
"And yet, what is this whole game but me trying just that?" the spirit murmured, now face-to-face with the screaming thief. "I've inherited a piece of your soul after all, it seems."
Smirking wryly, the spirit leaned in to brush his mouth against the man's he once had been - and who had once been his.
But by then the thief's lips had turned to sand, too.