Hayate (DEAD OR ALIVE)

Hayate is the eldest child and only son of Shiden and Ayame, the leaders of the Mugen Tenshin ninja clan, and was born to be the next leader of the clan. When Genra requested to Shiden for Ayane-the village's "cursed child"-to help him in his duties, Hayate treated the girl with kindness, which most of the clan did not give her. The two formed a strong bond, although Hayate did not know that Ayane was actually his half-sister, conceived when his uncle, the rogue ninja Raidou, raped Ayame when Hayate was only seven years old. Years later, Raidou attacked the Mugen Tenshin Village in an attempt to steal the clan's ninja technique, the Torn Sky Blast. Ayane attacked Raidou to defend Hayate and out of revenge for her birth, but was defeated. Hayate ran to her side, but when Raidou called him a "weakling" for hiding behind a woman, Hayate attacked him in rage. He used the Torn Sky Blast to fight Raidou, but was overcome by the ninja's superior fighting skill and the Torn Sky Blast was stolen from him. As both of their attacks collided, the resulting explosion threw Hayate into a tree, cracking his spine and sending him into a coma.
During the first Dead or Alive Tournament, Hayate was captured by DOATEC and was made to undergo various experiments as part of "Project Epsilon". After Project Epsilon was deemed a failure, Hayate was abandoned and was later found in the Black Forest of Germany by Hitomi, whose family took him in. Suffering from amnesia, he was named Ein and studied karate under Hitomi's father, later mastering it. He then joined the second Dead or Alive tournament to seek out his forgotten past, encountering many who knew him, including Ayane, Kasumi, Ryu Hayabusa, and Helena Douglas. He was eventually bested by Hayabusa in the tournament. Soon after, he regained his memory as Hayate and returned home to his village. In Dead or Alive 3, Hayate was assigned as the new leader of the Mugen Tenshin ninja clan, succeeding his father. He joined the third tournament to help Ayane and Ryu defeat DOATEC's new superhuman creation Omega, who was once Ayane's foster father and ninja master Genra. Although he felt it was his duty to defeat Omega as leader of the clan, Hayate was bested by Ayane, who then proceeded to the final round and killed her foster father, citing that it was a personal affair. He later returns in Dead or Alive 4 with Hayabusa and Ayane to defeat DOATEC and its latest creation, Alpha-152. He crosses paths with La Mariposa, who reveals that she manipuated them into attacking the Tritower. He appears as the final boss in Hitomi's story mode (as Ein), where he offers to help the latter rebuild her father's dojo is she could beat him in a fight.
In the live-action film DOA: Dead or Alive, he is captured by DOATEC after winning that year's DOA competition rather than being captured by DOATEC in his home village. Also, he is meant to test Donovan's newest invention rather than being tested on Project Epsilon. He is also the reason for Kasumi's entrance in the tournament, much like the first game. Donovan states that Hayate is stronger than Kasumi and that he has a "perfect blend of skill, timing and strength". Hayate and Ayane are also shown as lovers rather than half-siblings. Instead of ninjutsu in the games, the fighting style he used was Eagle Claw.