Illuge was a harpy-like demoness with a lizard-like mouth on her crotch area.
- Illuge: One of the first demons that attacks both Akira and Ryo towards the start of the manga.
- Illuge (OVA): Similar to her manga incarnation, she attacks Ryo and Akira near the beginning but is blown up by Ryo.
- Illuge (Grimoire): Unlike her last two appearances, Illuge was a supporting antagonist who worked for Sirene alongside Aleda and Wagreb. She fought against Jinmen early in the manga, only to end up getting killed by him and added to his shell. She merged with the human woman Sachiko Irima.
- Illuge (Gekiman): Attacks the pair yet again in the part remake, part autobiographical manga.