Demon Guns: Bolverk

Arcus Diabolus: Bolverk is a Nox Nyctores in the shape of a pair of handguns.

Information
Bolverk can attack targets through walls, Type XI: Optic Barrel being a dimensional collapse of sorts at a point in line with the barrel. It also serves as a limiter for Noel as it suppresses her emotions. This explains why she does not become emotionally unstable as Carl Clover or Jin Kisaragi. It is also revealed that in Noel's past she was attacked by a monster and suddenly Bolverk appeared right before her. Noel's emotions can break Bolverk, unleashing Mu-12. Bolverk is later restored - it is unknown how it happened.

During the Dark War, Bolverk had a multitude of owners, including one of the Ten Saints; Three. After their death, Bolverk was given to so many owners over time, its location eventually became unknown to even Jubei until its possession by Noel Vermillion.