Located inside the brain in a constant fetal position, the devil tumor is the physical representation of a magic users lifeforce. Even if a sorcerer is killed as well the body being destroyed, magic can resurrect the deceased sorcerer. However, if devil tumor is damaged or destroyed, the sorcerer cannot be resurrected. Exceptions to this rule require series of highly complex procedures and actions.
Kikurage is one of the few creatures that produces unique resurrecting white smoke. There is no need for the devil tumor to be directly in contact with the smoke: People will revive if their corpses are good condition.
Devil tumors are the source of the cross-eyes' black powder. From the magic user's brain, the cross-eye boss excises the devil tumor, and collects the tumor in airtight bags. Through cryptic methods, an excised tumor can release a finite supply of black powder for use.