Rou Kaioushin is a Kaioushin who emerged from the Z sword, where he had been imprisoned and bound to the ground by an ancient adversary, whom he described as an "incredibly strong evil fellow." He looks similar to the East Kaioushin but with an older, wrinkled face and a small mustache. Son Gohan releases him during the Majin Buu Saga when he accidentally breaks the Zeta sword while attempting to cut a block made of the strongest material in the universe. After his release, Rou Kaioushin agrees to help Gohan unlock his full potential to defeat Majin Buu, but only in exchange for the chance to date an Earth woman.
Centuries ago, Rou Kaioushin was considered quite handsome by his own standards until a hideous witch approached him and stole one of his Potara Fusion Earrings, putting it on herself. This instantly fused Rou Kaioushin with the witch permanently. Although he lost his good looks, he gained additional magical power. During the Majin Buu Saga, he sacrifices his life so that Son Gokuu can live and gives him the Potara earrings to fuse with Gohan on Earth. However, since he was already residing in heaven, his death had little effect other than producing a halo over his head.
In the Baby Saga of Dragon Ball GT, Rou Kaioushin assists Gokuu in becoming much stronger by helping him regrow his tail through a painful process involving a giant set of pliers.
(Source: Wikipedia)
