A/N This is an idea I got a couple days ago but forgot to write. It is pretty A/U to every world, and I'm not sure if I think Yuugi is actually insane in this or not, but at the very least, this is what I think would happen if someone said there was an Ancient Pharaoh within his mind. And yes, I know that more likely he would be diagnosed with Multiple Personality Disorder (Dissociative Identity Disorder), deemed safe toward himself and those around him, and put on medication, but it's more fun this way.
Plain white walls surrounded him. He felt like a prisoner of war subjected to white room torture. He looked down, strands of tri-colored hair, no longer spiked in its usual star shape, fell into his eyes as he peered at his plain white clothing. A pair of loose trousers and a jacket that forced his arms around himself.
He had been smart at first. He hadn't told anyone about the spirit possessing his puzzle, for fear this would happen, but eventually, it just sort of slipped. His friends would look at him strangely, concern shining in their expressions, each time he brought it up. So he stopped talking about it. His grandfather asked if he was sick and wanted to lay down when the boy had tried approaching the subject, so he agreed that he should and never spoke of it to him again.
Why was it that he was the one to end up like this? Others had the same thing happening, right? Bakura and Marik, they were crazy, not him!
He drew into himself, entered his mind, and saw the door to the right he dared not open. Yuugi wanted to forget everything about the spirit. The three thousand year old Pharaoh, who right now, was his only friend…his only companion.
The boy ignored the other door, pretending it was nonexistent, and entered the room on the left, carefully stepping over the last few toys that littered the floor. His innocence had gradually begun to fade and all that was left in his room of mind was a bed, an untidy dresser covered in frantic scribbles and messy writing, and the last of his innocence portrayed in the toys and games that guarded the door. On his dresser was the last reminder to him that what he saw, what he experienced, had been real.
A pack of Duel Monsters cards.