In the popular anime series One Piece by author and illustrator Eiichiro Oda, Monkey D. Luffy learned to use Haki while training with former pirate king Gol D. Roger's right-hand man Silvers Rayleigh.
Devil Fruits may grant special abilities, but they are very rare to find. Meanwhile, Haki can be utilized by every living being. While the concept existed before the One Piece timeskip, it wasn't ...
Luffy and Rayleigh say goodbye to Jinbe and go to Rusukaina Island, where Luffy will be trained under Rayleigh. Rayleigh explains to Luffy about Haki, demonstrates for him on a wild giant elephant.