Carl is a
young boy who, like Noel and Jin,
was also 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 Deus Ex Nirvana, a Nox Nyctores in the form of a
marionette, often blamed for "Insanity" in the user when in fact it
only amplifies its owner's preexisting desire to kill, similar to Jin's sword
and Noel's pistol.
After several people attempted to disassemble or remove Nirvana from him, Carl
has become 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.