Takemaru

Takemaru no Setsuna was a character who appeared in the third Inuyasha movie Inuyasha the Movie 3-Swords of an Honorable Ruler where he is one of the main antagonists.

Overview
Takemaru no Setsuna was a jealous human Samurai lord who fell in love with Inuyasha's mother Izayoi. His jealousy became so great at he attempted at her life and impaled her in her sleep while she was still pregnant when the Dog General, Inuyasha's father came to save her. Setsuna appeared before the demon warrior and attempted to take him on but his challenge was easily brushed aside, costing him his left arm. Not wanting to let the dog demon take Izayoi away, he orders his soldiers to immediately burn down the castle. Setsuna's attempt to keep her for himself was in vain as the great demon utilized Tenseiga to revive Izayoi, allowing her to escape while he fought the desperate Setsuna to the death. Setsuna is killed offscreen when the demon draws forth Sou'unga and claims his life with the Dragon Twister, although the dog general later limped away with fatal injuries.

Later on, the sword Sounga, free from Saya wanders around the land searching for a suitable host after it is driven away by Sesshomaru. Reacting to the lingering thoughts of Setsuna, whose skeleton resided in the charred badlands. the evil sword revived him and fed on his desire for revenge against the Dog Demon and his ilk. To further sweeten their vengeance, Sounga gives Setsuna Sesshomaru's left arm which lopped off during the demon's scuffle with his younger brother to wrestle control over Tessaiga. With blade in hand, Setsuna transforms into a demon of death and destruction and takes command of a nearby castle, killing its inhabitants and soldiers which then whose corpses he uses to raise an army of evil undead as he erects a dark castle to begin his conquest. As Inuyasha's and Sesshomaru's groups storm the castle, Setsuna comes face to face with Sesshomaru himself with Tokijin at the ready.

Though Sesshomaru is able to easily overpower him in terms of strength and even cuts him down, the Sounga simply regenerates him, mocking him that he can't be killed by another weapon already steeped in evil. It is from this realization that Sesshomaru instead draws forth Tenseiga and finally slays him, freeing him from Sounga's control. His last thoughts are of Izayoi and regretting his mistakes as his body is reduced to bone once more before his skeleton is crushed by the temple's transformation.