Kiki (鬼気, Demon Energy) is a special type of energy that exists within the Land of Demons. It is a type of energy left behind after a demon had been slain or is released upon a demon entering the human world. This type of energy is utilized by the Ryoushi Clan in their main form of demon hunting. Since demons can only be killed by demons the Ryoushi's use this energy to slay them. The energy can be stored within to body by utilizing a special technique created by the Ryoushi Clan. The properties of this energy are mainly enhancements such as making someone faster or their sword sharper, as well as the ability to kill and harm demons. Due to the Ryoushi Clan's years of utilizing the energy it will poison those who attempt to absorb it that have not been born into the clan.