During the Warring States period, he did battle with Talpa and banished him to the Nether Realm over one thousand years ago. He is responsible for the creation of the nine mystical armors, which he forged from Talpa's discarded armor after defeating him.
When Talpa returned one thousand years later, so did the Ancient One, but this time to assist the Ronins in their struggle against the evil emperor. On many occasions, he would help them in defeating an opponent that was too strong for them. When he came across the leader of the Dark Warlords, Anubis, he tried to show him that he was being used by Talpa; that by gaining strength for himself, he was only gaining it for Talpa (i.e., he was only being manipulated). This led Anubis to question his place among Talpa's ranks, and eventually to escape.
When it came time for the Ronins to make an assault on Talpa's castle, the Ancient literally turned himself into the bridge that would lead them along the way. This was his sacrifice, but although he died, his role did not end there.
After the Ronins defeated Talpa for the first time, Anubis reappeared in the Ancient's attire, though this didn't mean that Anubis was the Ancient One, because that role was to be later filled by the true heir and last of the Ancient Clan; Lady Kayura.
The Ancient One makes one last appearance in the 3rd OVA, Message. During various flashbacks, the Ancient was seen during World War II at the ruins of a temple. He discovered the sealed box that contained the Armor of Strata and it was there he discovered the ghost-child, Suzunagi. He felt sorry for the girl because she was filled with hatred and revenge; however, he knew she was trouble when she attacked him, claiming that the armors were evil. He, along with the newly revived Strata Armor, chased Suzunagi away and with that, the Ancient mysteriously vanishes. The Ancient is voiced by David Kaye in the English dub.