Invisible「インビジブル」 is a fairy who only shows herself to Deathpierce and acts as his informant.
She is a very small fairy with angel-like wings and short pink hair. She appears to be nude, save for a pair of pink lacy stockings that cover her legs.
In the anime, she is a fully clothed, with a white dress and white stockings.
She is apparently very shy, only showing herself to Deathpierce and whispering to speak to him instead of speaking aloud, likely because she doesn't want anyone else to hear her.
Invisbility - She can turn self invisble to be undetected by anyone even the higher rank demons weren’t able to detect her as she was the only spy to return. She can make herself visible to select people example being Deathpeirce.
Invisible was tasked with acting as his spy to survey the Ten Commandments actions, as was the only such spy to return. Later informed him and his group about the devastation in northern Britannia, Camelot's downfall, and the goings on at the Great Fight Festival at Vaizel.
She has been friends with Deathpierce since he was a child and he is the only one she allows to see her or will talk to.