"Kaio-ken (界かい王おう拳けん Kaiōken, lit. "World King Fist" or "Fist of the King of the Worlds") is a technique invented by King Kai. It multiplies the user's ki for a "heartbeat" and turns their aura crimson - amplifying their power and speed to overcome previously stronger foes at the cost of extreme bodily recoil. Strong ki control is required in order to wield the Kaio-ken properly."
