Genkai

Genkai first appears when she holds a tournament to decide who would be her successor. Yusuke Urameshi wins and defeats the demon, Rando. She trains Yusuke in the Spirit Light Wave Fist (Reikō Hadō Ken) aka the Spirit Wave in the English dub and coaches him to the extreme. Though she may appears nasty towards Yusuke and the others, she truly cares about all of them, and tries to lead them down the right road.In the past, she was one of the most powerful human fighters ever to be known in both Ningenkai (Human Realm) and Makai (Demon Realm), alongside with her fighting parter and suggested lover, Younger Toguro. However, Toguro became depressed and changed after a yōkai named Kairen (there are alternate spellings) killed all of his students that he taught at his dojo. When he was invited to the Dark Tournament by Kairen, he and Genkai along with some others fought and won. His wish was to be given a powerful body, the body of a yōkai that would serve him for whatever purposes he wanted. Because of this, Genkai became angry and her wish was simply never to be involved in the tournament again.She left to her own temple, and did not speak to Toguro until he pushed her apprentice Yusuke into the Dark Tournament. But due to her reputation she chooses to go in disguise to avoid becoming a target for the yōkai at the Tournament. During the second round Genkai recognized the three human fighters as she is an acquaintance of their master and helped free them from Dr. Ichigaki's control. After being trapped with Hiei in Ruka's barrier during the third round, Genkai had Yusuke come with her to a secluded cave and revealed that she was the masked fighter all along. Knowing that Yusuke was still not strong enough to defeat Toguro and that she is too old to defeat him either, Genkai was willing to risk Yusuke's life by transferring most of her Reiki through the Reiko Gyoku into him so he could become strong enough to face Toguro.After unbearable pain and agony Yusuke was finally able to fully absorb the Reiko Gyoku, Genkai left to the semifinals and was able to defeat Shishiwakamaru and Suzuki advancing Team Urameshi to the finals. After that she confronts Younger Toguro and he kills her, but is able to explain to Yusuke her connection to Younger Toguro and warns him not to become like Toguro. During Yusuke's battle against Younger Toguro she briefly possessed Yusuke's Reikaiju beast Puu and urged Toguro to kill one of Yusuke's friends to draw his true power. After the battle was over, Genkai briefly appeared to Younger Toguro in her younger form to try to convince him of not going to the Darkest Hell (Limbo in the English version) for his final destination. After that she was resurrected due to Yusuke's wish of wanting to see her again.For the remainder of the series Genkai played a supporting role. First in the Chapter Black saga where three high school students, Asato Kido, Yuu Kaito, and Yanagisawa Mitsunari appeared before her with strange powers. Knowing that Yusuke was going to get involved in this mission, Genkai arranges for the three boys to kidnap Yusuke and test his friends in hope of training them to the idea that they can't jump into this new mission irrationally because they don't who their new enemies are or what powers they have. After that Genkai, Kaito, Asato, and Yanagisawa assist the group in finding the mastermind Shinobu Sensui. During the battle against Gamemaster (Tsukihito Amanuma), Genkai reveals how good she is at video games by easily winning the Fighter Jet game. At the end of the saga, when Genkai and Yusuke were saying farewell to Kaito, Kido, and Yanagisawa, Genkai advised them never to use their powers again otherwise they would never be accepted in the Human Realm.During the Three Kings saga when Yusuke was going through some personal problems, due to the fact he has been reborn as a yōkai and is now considered too dangerous to live in the Human Realm. Genkai directed him to Sutou Kuroko a former Spirit Realm Dectective in hopes of her being able to talk with him. When that didn't work Yusuke had everyone gather at Genkai's temple where he said his goodbyes to Genkai and everyone else before leaving for the Demon Realm. Six months later, Kurama had Genkai aid him by having her train Rinku, Chu, Touya, Jin, Shishiwakmaru, and Suzuki for six months in hopes of fulfilling his promise to Yomi of delivering six powerful A class fighters. At the end of the series Genkai called everyone to her temple and announced her decision that should anything happen to her then Yusuke, Kazuma and Shizuru Kuwabara, Yukina, Keiko Yukimura, and Kurama will inherit her temple as her dream is to have it become a home for any yōkai that choses to live peacefully in the Human Realm.Genkai has also appeared in the Yu Yu Hakusho: Poltergeist Report movie, where her temple was used as a base for Team Urameshi during the Netherworlds invasion.One of Genkai's special powers is when she manipulates Reiki to a certain extent, Genkai can temporarily revert to the state of a twenty year old woman. This is due to the fact that her cellular makeup automatically shifts to the form of the time of their life when the individual in question was at the peak of their power.Although Genkai is of advanced age, and her physical and spiritual strength had gone down, she is still a fighter to be respected and feared, Even after she gave up most of her power to Yusuke, she still is capable of using some Reiki.