First, I want to make clear that I got the inspiration to this story from "Kid Cipher" by Soulscarcity13, and therefore it maybe are a few similarities, even if I'd tried to hold them out of this story! Now; enjoy!

Prologue

The House in Godric's Hollow, England.

With a flash of light a certain omniscient dream demon appeared in the home of the Potters.

A woman's death scream filled the air. Bill sighed delightful. Death screams were nearly so enjoyable as his favourite song – 10 hours of Rising Shepherd Tone.

But no time for this. He wanted to see what's going to happen with the horror of the Wizarding World. An hour ago he'd foreseen that the events tonight should choose the destiny of the world. Either Lord Voldemort should die, or triumph.

Bill floated into the room where the final "battle" were standing, in the same second as Voldemort screamed in horror and died. Bill took a second to enjoy the scream and the taste of the man's horror, but knew he didn't have so much time before these "good" wizards should be here.

Bill looked at the thing which saved the world. A crying infant named Harry Potter.
Bill raised a hypothetical eyebrow. This baby defeated the Dark Lord? He took a look inside it, or "him" if you was fussy, and loved what he saw. The kid were filled with dark magic. The bleeding scar on his head were the proof. Bill snapped his fingers and a rag appeared and removed the blood, and Bill healed it so it wouldn't leak out more.

"I think I keep you, kid." He said to the infant, thinking about everything he could learn this child. Harry Potter would be a perfect assistant. And the faces of those Pines when he had a human child of his own, to raise to be just as he wanted him to be… Priceless!

He took up the infant in his arms and created a portal to Gravity Falls.