I received this t-shirt as a gift, but I have no idea what the text says. I would appreciate any help.
In the anime One Piece, it means Conqueror's Haki or Haoshoku Haki:
Haoshoku Haki is a rare form of Haki that cannot be attained through training. Only one in several million people have this ability. This type of Haki allows the user to exert their willpower over others. It is said that whoever possesses this type of Haki has the qualities of a king.