During the events of Nightmare Moon's return, a strange young man appears in Equestria. Just who is he? Not even he knows. For some reason he can't seem to remember anything except his name. He seems fun-loving and kindhearted, but these strange abilities leave some skeptics.
Just who is Monkey D. Ace?
One Piece / My Little Pony: Friendship is Magic crossover with a few twists added into it.
(Not Portgas D. Ace or Monkey D. Luffy.)