Crepus

Devil of Evening, Crepus (のクレプス Yoi no Majin Kurepusu), or simply known as Crepus, is the Partner Z/X of Yamato Tennoji (Le ciel).

Possessing good-looking, succubus-like appearance. She is an assassin sent by Domeki Foundation to Le ciel, and is ordered to kill him if he failed a mission or planned to escape. She usually cooperates with Le ciel as his partner to achieve a mission, but it is impossible to understand her true intention beyond her mysterious looks and words.

Story
To be added.