Black Percher

Background
Black Percher or Pest is the Demon Lord of the Black Death. She appears late in the series and challenges the "No Names" to a Gift Game with her servants Weser and Ratten.

Appearance
She has red short hair with long bangs and red eyes. She wears a black dress with white buttons and polka dot skirt. This is the same design for her detached sleeves and her bow in her hair. She has a blue horn on a brown stirring attached to her waist.

Personality
She has a quiet and proud personality, even during fights she is calm. She is also quite insidious as she would kill all the participants of the Rising of The Fire Dragon Festival just so she could get the powerful No Name's problem children to join her community.

In later parts of the story she is shown to lose her temper as well as being angry especially to Shiroyasha.

However, this personality changes after spending some time in [No Name] when she was resummoned by Jin Russels. Initially taking much pain to make fun of the members and training them in their Gifts, she shows much  more emotions besides sadness and loneliness now.

Relationships
Ratten - She is Ratten's master. She appears as playful, yet is very loyal to Pest. She got jealous of Wesser when Pest gave him divinity.

Weser - She is Weser's master. He serves her loyally and was given divinity before another duel with Izayoi.

Jin Russell - He was given a ring to summon her as a comrade of the [No Name]. From that time on, she has been helping out with the daily activities as a maid. (Shiroyasha's personal maid costume collection set) Later on in the series, she is shown to grow closer to Jin.

Izayoi Sakamaki - She respects this monster like human. Precisely because of his monster like powers that are totally unexplainable and he kind of treats her like a smaller sister of his. Dragging her to the bath and threatening to bathe her personally if she doesn't get along with Asuka. She also joins in the fun with the problem children in volume7 where she takes part in his plans to convince the crowd through unconventional means. Like with his fist.

Kudou Asuka and Kasukabe You - Other than practice sessions, they do not usually come into contact. She likes to tease others that she don't usually realise that she had passed the limit of their capacity and have felt hurt. As seen in Asuka's case and it is fortunate that the case was settled by the appearance of Izayoi who made it seem more of a gag comedy.

Highness - He was the one who held the books to summon her to this world. She knows nothing much about him other than the fact that he is the leader of Ouroboros and that the only person ever to damage him slightly is Izayoi.

Plot
Pest was one of the remaning survivors of the Grim Grimoire community, believed to have been annihilated by another stronger community. She arrives at the Fire Dragon Festival alongside her subordinates to recruit new members by force for a new community that she sets up, and wants the Problem Children, the no-names, and Shiroyasha as her members, intending to kill them if they disagree.

It is revealed later that she was summoned to be a comrade of the Ouroboros Alliance of Demon Lords. And that her appearance in the North was arranged by Sandora's older Brother in an attempt to help his sister gain fame and experience in defeating Demon Lords.

Currently, she has sworn loyalty to the [No Name] Community after having much fun with the members and having gotten used to the life there after being summmoned by Jin. During their time in the prison of Sandora's castle, Jin also promised to help her fulfil her wish after the Community finds its lost members. Causing Percher to swear her loyalty to him there and then.

Gift
Black Death: Black Percher's gift. Black Death's capabilities are to be able to shoot black fog-like substance which can rival Sandora's gift and implant a disease with a time limit in where it can kill the infected person, the gift can also use as a defense blocking Sandora's fire and Black Rabbit's lightning.

Trivia

 * She was shown in Volume 6's cover.
 * She died in a prison when she was young and infected with Black Death.