Yoma no Oni

Kuni Yoma was a Crab Clan shugenja. On an incursion into the Shadowlands with a group of Crab, Yoma became possessed by an oni that was to become Yoma no Oni. Yoma fled to Kuni lands and took refuge in Shihoden Temple. After being tracked down, Yoma used his abilities to assault his pursuers and the monks of the temple. A Kuni shugenja sacrificed his own life to burn Shihoden Temple down around Yoma, and the temple's monks with him.

Characteristics
Oni no Yoma appeared to be human, but was able to discard that form. Yoma's body would burst open, releasing an enormous swarm of aggressive insects, each the size of a man's index finger. Yoma had a high resistance to jade and was somehow completely immune to crystal, and was vulnerable only to fire.