When it comes to Haki, fans have seen quite a lot of powerful users of this ability in One Piece. This spiritual power exists within everyone, but not all of them can tap into it, and even those who do, cannot make the best use of it. Haki is a monstrous ability in One Piece that can take one far in the New World. This ability is wielded by the most powerful individuals in the latter part of the Grand Line, but, most of them also have Devil Fruit abilities.