Kagetatsu Nishikida

"You're not a human. Are you a monster ? But I sense no evil in you. Forgive my rudeness."

- Kagetatsu upon meeting Daigo.

Kagetatsu Kojuro Nishikida (錦田小十郎景竜) or simply Kagetatsu Nishikida, was an ancient swordsman that appeared in Ultraman Tiga.

History
A long time ago, Kagetatsu was wandering at the Mount Sakuna when suddenly a giant demon monster named Sakunaoni and rampaged. He dueled the evil demon and defeated it by slashing the monster into parts and buried while sealing it's spirits in a mountain. He left his katana within a special shrine that build at the centre of the Mt. Sakuna in order to maintain the seal and left.

But as time passed, three robbers stole his katana in order to sold it, unknowingly broke the seal and reviving Sakunaoni. He possessed one of the robbers and regain his katana while heading to Mt. Sakuna. Daigo followed him as he revealed that he was born with the ability to see various supernatural spirits and dedicated his life to fight monsters. He was supposedly replaced the sword that sealed up the monster with another but he was too late. Sakunaoni appeared in front of them as a spiritual floating head temporarily and revives. Kagetatsu can no longer defeat it due to its immerse strength but he later asked Daigo tocontinue his legacy.

Daigo transformed into Ultraman Tiga, at the same time, having his previously injured left hand temporarily healed. Tiga quickly attacked the demon, who fought back with martial arts but was flipped overhead but landed on his feet and fired with his Nitro Beam. While Tiga managed to get behind him and attack, the demon warrior’s second face blasted him with his white smoke, stunning him long enough for Sakunaoni to plunge his fist into the mountain and unsheathe his ancient blade. Sakunaoni quickly attacked Tiga with the blade but Tiga managed to fight back, forcing the oni to play dirty. He put his sword behind his back, then took Tiga off guard by driving the hilt into his gut before tripping him with the sword. Tiga could barely stay out of the way of the blade and Sakunaoni began to beat down Tiga with martial arts and the hilt of his sword. But as Sakuna-Oni charged in for the finishing blow, Tiga used the Ultra Singled Outtakes and caught the oni’s sword. The Tiga Slicer had sliced through Sakunaoni’s sword and neck so quickly that the demon had appeared unharmed until his sword fell in half and then his head toppled from his shoulders.

The oni’s body dissolved into flames but the monster’s head suddenly launched from the ground and sank his teeth into Tiga’s shoulder, biting so hard that Tiga’s color timer started blinking and he couldn’t remove the demon. But as Sakunaoni’s victory seemed at hand, his ancient enemy, Kagetatsu, sent his katana flying through the air and into the oni’s head. Sakunaioni bellowed in pain as the holy energies contained in the blade surged through his head, obliterating the demon and ending his reign of terror once and for all. Following the fight, the samurai could finally rest in peace, granting his title as guardian of Japan to Ultraman Tiga.

Trivia

 * Kagetatsu was said to be a swordsman that wandered around to defeat monsters and restore peace. Similarly, after Tiga duel with Sakunaoni, he passed the torch to Daigo/Tiga as Earth's protector.
 * An alternate Kagetatsu appeared only in manuscripts and mentioned in Ultraman Cosmos Episode 18, where he sealed the evil demon, Renki.