Rainenmaru

Rainenmaru was one of Suien's summons who appeared in Naruto: Mission: Protect The Waterfall Village! (novel).

Personality
Rainenmaru was very loyal to Suien. He was also violent towards his opponents.

Appearance
Rainenmaru was giant black koi.

Abilities
Rainenmaru had incredible speed and was powerful enough to take down Ryūrimaru and Naruto Uzumaki with a single blow.