The master of Kusumabura, an underground city which used to be called the Flower City, before the clan was destroyed by Taishaku-ten's army during the Holy War. Kumara-ten wanted to defeat Taishaku-ten and take his place as tentei, but in order to do that, he needed the power of the Shura-to, which he heard could only be awakened by using the blood of one of the Ashura clan along with a lunar eclipse. Which is why he captured Ashura.
(source: Nishi's RG Veda Gallery)