Lunarken (ルナーケン, Runāken) is a moth-themed Inga Horror who is normally dormant until the night of a full moon where her bloodlust is at its zenith. Her host serves as a puppet body while her actual form is the orb hovering around it.
Lunarken came from inner darkness of its host, a suicidal woman who attempted to commit suicide. As the woman apparently died before the Horror possessed her, Lunarken instead used her body as a host and puppet body - its true form is the glowing orb hovering about it that acts as a weapon. The Horror terrorized two men and a high school girl in its warehouse nest before being slain by Kouga.
Having possessed a woman who attempted to commit suicide over a man's insensitivity, Lunarken preyed on Hitoshi Morino, Hanezawa, and a high school girl when the three were in a stand off in a warehouse. Luckily, brought to the warehouse by a moth containing the host's final thoughts, Kouga Saejima knocks out the normal humans before killing Lunarken.
- Horror Powers: Lunarken is a Horror that matches an average Makai Knight in strength. In addition of dispersing into moths and reforming at will as well as regenerating her host body indefinitely, she fights with a fiery yellow moon-like orb to smash things with. The same orb can generate spikes to increase its destructive capabilities. However, the orb itself is technically the Horror's true form and core - destroying it will ensure the Horror's death.