Black Imperial Sword Judecca

The Impel Arm, Black Imperial Sword Judecca is a sentient living weapon of great power. This weapon can only be used by a Magic King or Magic King Candidate who has gained access to three Archives.

It has shown the ability to change into a sword shaped pendant for ease of carrying, and mentioned it can also assume a human form, even a female one.

It can channel great amounts of magic, unleashing devastation sufficient to destroy the Sky Library.