Yu Yu Hakusho Saga of the Three Kings Episode 4 Return to Demon World ( Air Date 1994-09-10 ) Genre Animation, Action & Adventure, Sci-Fi & Fantasy category. Overview "Control of Demon World is divided among three rulers: Raizen, Yomi and Mukuro. From his deathbed, Raizen has invited his descendant, Yusuke Urameshi, to return to Demon World to train under him for one climactic battle. Yusuke's first challenge is to defeat his ancestor. If he cannot defeat one of the three kings, how could he expect to stand up to the other two?!".