Carl Clover

Race: Human
Birthday: May 5
Birthplace: 2nd Hierarchical City of Iwatsuchi
Height: 144 cm
Weight: 35 kg
Blood type: AB
Hobbies: Violin, chess
Values: His sister
Likes: Cookies
Dislikes: Lies

Carl is a young boy who, like Noel and Jin, was a student at the Military Academy, but dropped out without warning while Noel and Jin graduated. Currently, he is after Ragna's bounty and the Azure Grimoire, leading him to become a vigilante. He travels with a maid-like puppet called Nirvana, whom he believes to be his sister Ada. He is unwilling to see that she is in fact the Nox Nyctores Deus Machina: Nirvana, a causality weapon in the form of a marionette which amplifies its owner's desires to kill. After several people attempted to disassemble or remove Nirvana from him, Carl became extremely paranoid and possessive over his "sister."
In the end it is unknown whether Carl is insane or if Nirvana is truly Carl's sister, Ada.

Interestingly enough, one of the "Teach me Dr. Litchi" episodes reveals that Carl's glasses are what gives him the ability to talk to Nirvana, as well as mailboxes and telephone booths. It seems that Valkenhayn has some history with Nirvana, as he is able to talk to and understand her just as Carl is. During a conversation, Nirvana tries to attack him but he mentions that they "are not enemies anymore" and manages to persuade her to calm down.