Blade of the Immortal - 1x01 - Season 1, Episode 1- Followmy.tv

Manji visits a priest in order to confess his sins, namely killing his lord and 100 of his retainers, an act that earned him the moniker "Killer of 100." The priest, who is actually a con artist, attempts to kill Manji by shooting him in the forehead, but Manji kills him and regenerates the wound. Manji returns to his home to find Yaobikuni, a nun who placed "sacred bloodworms" into Manji that make him immortal, and his sister Machi. That evening, Machi dreams of the time when Manji was forced to kill her husband, a police officer purusing Manji, causing her to lose her mind. After the dream, she wanders into the night and is captured by a group of ronin led by the brother of the priest Manji had killed. Manji pursues Machi but is unable to prevent her from being killed. In response, he kills every member of the ronin group, and upon returning to Yaobikuni, declares that he will seek redemption for the 100 men he killed by killing 1000 evil men.