Sanzan

Sanzan is a strange entity that was in Seraphimaru's ancient story that Paul Gekko was possessed by it.

Background
According to Seraphimaru, Ages ago there was a terrible darkness that shrouded the planet Dens. THen the Sanzan came and expelled the darkness bringing peace to the Planet until he was pursued by the group of Keyblade wielders including Sora and Riku. The Sanzan fought back to send the pursuers back to their own nests but the strength it has left was too much to redeem. So the entity decided to transfer it's spirit to the the Descendant of Susano. The Sanzan's spirit remained within Paul Gekko for the millions of years until the end of the Galactic Empire's reign. Sanzan thanked Paul Gekko and Fortress Gundam for bringing peace for the people and suddenly transformed into a legendary sword Excalibur.

Appearence
Sanzan's appearence resembles the Sestern from Panzer Dragoon Series.