Undying Love?

Yugi opened blurry eyes in time to see a dark form disappear into a flash of golden light. Struggling to wake up, he managed to focus on the source before the light completely disappeared. The was coming from the Sennen Puzzle: More specifically, the Horus eye in the middle of the completed puzzle. The last piece meant to be placed inside.
‘Does someone live in there?’ Yugi wondered in amazement. His innocent mind allowed such thoughts, partly why he was so shunned and ridiculed by his peers. Yugi carefully stood, expecting himself to still be battered and broken from the beating, the clock on his desk only reading thirty minutes past where he had last seen it. However, the petite teen was shocked to find every last one of his injuries had been magically healed somehow. He rushed over the the Sennen Puzzle and took it happily in his hands.
“I knew it! I knew someone would be around for me if I finished this!” he cried happily, leaping into his bed as he joyfully clutched the puzzle to his chest. Yugi lay on his back and rubbed the Horus eye lightly. Nothing happened. “So you’re not a genie...” the teen mused, a smirk forming on his face. “I know you’re in there, you can’t hide from me! Come out, I wanna meet you! And thank you properly too!” he added as an afterthought, his euphoria almost causing him to forget his manners. The Horus eye glowed brightly, but for some reason the light didn’t blind Yugi.
Black clouds swirled out of the middle of the light and landed next to Yugi’s bed. A darker, older version of him materialized, causing Yugi to gasp. The vampire looked at him with uncertainty.
“Are you all right, little one?” he asked, his heart still full of concern. Yugi pouted. He hated being called little.
“I’m not ‘little one’! I’m Yugi! Yugi Mutou!” he said stubbornly, only making his pout all the cuter. The vampire smiled gently, pearly white fangs glinting slightly as his lips parted. Yugi’s already wide amethyst eyes widened further. “You’re... a vampire?”
The vampire’s smile swiftly disappeared. He hung his head, wondering if he had just blown his chance with the boy. He sighed and said, “Yes, I am. My name is Yami, if you would like to know. At least, that is the name I was given after being sealed away.”
“What’s your real name?” Yugi asked innocently, causing Yami to look at him in surprise. The vampire had expected the boy to demand to know why he was sealed away, not ask him about himself. The vampire’s crimson eyes blinked slowly as he tried to process the shock the teen had just put him through.
“I- Well, um.. It’s Atemu,” he stammered, completely caught off-guard by the boy’s innocence. Seeing as how Yugi was repeatedly beaten day after day, he expected the boy to be... much less optimistic to say the least. Yugi grinned.
“Well, then your name is Yami Atemu now! Or would you prefer Atemu Yami?” he said brightly. The vampire was flabbergasted by the teen’s bright and cheery behavior.
“Um... Yami Atemu is fine...” he mumbled, not sure how to react. Yugi’s grin turned into a sweet smile.
“Okay, then, Yami. I haven’t thanked you yet for saving my life. I know it was you who did something to heal my injuries, I saw you disappear into the puzzle as I woke up,” Yugi said cheerfully, but more seriously than before. Yami sighed. He was glad to know that Yugi’s joyful demeanor was no facade, and was saddened at the same time that one simple act of kindness had brought the boy so much joy that the vampire knew there was little of it in the teen’s life. Yami watched as Yugi rooted around his room, searching for something among all the scattered toys and clothes. Finally, he found what he wanted and held it up to Yami.
It was a card. On the front was the picture of Osiris the Sky God monster, a beast that existed when he ruled as Pharaoh. Yami took it in shaky hands, staring at the exact replica the drawing had of the dragon. Yugi noticed Yami’s reaction and beamed, happy that he could make his savior happy.
“That’s Orisis-”
“-the Sky God, I know,” Yami finished. “He was a powerful beast from ancient Egypt. Along with me, he and all the other Shadow Creatures were sealed away. I was sealed away as a guardian to protect them from falling into the hands of evil. I cannot believe someone has managed to harness their magic and bring them back into this world...”
“Wait, you mean Duel Monsters are REAL?” Yugi nearly shouted. Yami looked over at the boy, fearfully expecting horror and was once again shocked when he saw excitement plastered on the teen’s face. Yugi laughed at the bewildered look on Yami’s face. “I was always called crazy whenever I voiced this when I was little, but I can talk to certain Duel Monsters. Dark Magician is my favorite, and he once told me I looked like someone he once knew. That was you, wasn’t it?”
“So Mahado still remembers me after all these years...” Yami muttered, more to himself than Yugi. Suddenly, Yami’s face became serious as his gaze fell upon the card in his hand once again. “Have Obelisk the Tormentor and Ra the Sun God been made into cards as well?”
Yugi nodded, and Yami’s heart sank. Yugi looked at his new friend’s crestfallen face and quickly said, “But they weren’t released to the public. I was given Osiris by the inventor of Duel Monsters himself, Pegasus J. Crawford. He said it belonged with my puzzle, and once I completed it, the other two would come to me as well. I don’t know how he knew about the Sennen Puzzle, but he DID have a creepy eye engraved to look like the Horus eye.”
Yami nodded, taking in all of this information. So this Pegasus person created Duel Monsters, had a Sennen item, and was cautiously giving the most powerful cards to Yugi. The vampire wondered exactly who this man was, and how he knew so much of the ancient past forgotten by Time himself?