Before Fire-Fist Ace could be executed, he’s saved by an old childhood friend of his, Sunset Shimmer. She’s been watching and learning from the shadows, ready to show what she learned.

One Piece World infused with magic from Equestria, that allowed all the strange and weird things to happen in the first place. As I really can’t explain how a world like One Piece can work. So it’s all magic is the reason why.