Years before the main Yu Yu Hakusho story, Toguro Ototo (Younger Toguro)defeated Karasu and Bui in combat, giving Bui a scar on his forehead in the process. They both swore their lives to the Toguro’s while they trained to defeat them one day.During the Dark Tournement Saga, Bui fought Hiei in the final round and lost, but was despite his begging for Hiei to kill him was refused, living him the only member of his team to survive.
Powers and abilities
Bui typically battled with a large set of Samurai-esque armor and wielded a large ax.Although his true power was in fact restricted by the armor in the form of his “battle aura” which offered him excellent defensive capabilities and flight.