There was a reason why a Horcrux was not supposed to be attached to a living person. Something that Harry and Voldemort learn the hard way when Lily's protection failed after Harry left Privet Drive for the last time. But that doesn't mean it ended up being a bad thing. Harry / Voldemort SLASH and MPREG

What if the sliver of Lord Voldemort's soul in Harry's scar wasn't a Horcrux at all. Instead, when the Dark Lord's curse rebounded that Halloween night, a piece of his fractured soul sought out the one thing that had felt similar, equal even. And after his abuse suffered by the Dursleys, Harry shows up to Hogwarts with a very different outlook on things. Dark Harry! TR/HP SLASH

Legend got the story of the Deathly Hallows wrong. Death had introduced them into the mortal world but not as a reward for cheating him. They didn't make one a Master of Death, either. They had really been introduced for recruitment purposes, a fact that Harry came to discover after losing Sirius and resolving to seek revenge on those who had wronged him. SLASH. HP/OMC & HP/Death

Wormtail screwed up the resurrection ritual and now the Dark Lord has to deal with the consequences of being reborn in Harry Potter's body. However, he soon realizes that not only does he find himself in a more attractive body but he now has the ability to take Hogwarts and the wizarding world from within… and maybe, just maybe, a chance at love. SLASH (DL as HP)/SS

Hogwarts became sentient over the centuries and the sheer amount of ambient magical energy that it absorbed allowed it to become self-aware in other universes as well. The Castle soon began to meddle in the lives of witches and wizards. Harry Potter and Tom Riddle were her favorites and one day Harry finds himself in 1942. Slytherin Harry! HP/TR SLASH

A curious thing happened to Hogwarts with all of the ambient magical energy surrounding it. After watching the same story play out in countless worlds, it has had enough of the violence between Tom Riddle and Harry Potter. The Castle decides to intervene and bring them together to see if it can give them a different future. NOTE: Reworked into HOGWARTS: A HISTORY OF MEDDLING!

Voldemort had it all figured out: he was going to use Harry Potter's blood and reclaim his old body in the cemetery. However, he notices that Harry's scar is a Horcrux and quickly realizes that he has a once-in-a-lifetime opportunity. Not only can be reborn in a more attractive body, but he can take Hogwarts from within and reshape the world as he sees fit. Slash (DL as HP)/TBD.