The Demi-Humans' Infinite World Conquest

This is the story of a demi-human boy whose world was destroyed by a powerful Reincarnator. He wanders through an infinite number of worlds, seeking strength so he can take revenge.

Current worlds: Fate/Zero - Highschool of the Dead + Resident Evil - Guilty Crown - Naruto - Vampire mashup world - X-Men/Marvel - Gantz - Middle-earth - DND series - FGO - Final Battle