Ten Fighters of The Underworld (jap. 魔界十人衆, Makai Jūninshū) were lesser soldiers and assassins of the Empire ruled by Gaia.
Their commander was Mugen. They were sent to search for a dog who masters Zetsu Tenrō Battōga and to find Reima's Palace. While searching for Gin, they killed Bemu and Bill and ripped off Hakurō's paw.
Only their commander survived, by running away.