ClavisAngemon

ClavisAngemon is a Virtue Digimon and carrier of the X-Antibody It is an Angel Digimon which protects the "Zenith Gate" between the Digital World and the outside world. The "Zenith Gate" is sealed by means of 360 doors, and "The Key" held by ClavisAngemon is used as the master key to every door. "The Key" is a special key that only ClavisAngemon can handle, so one can say that ClavisAngemon itself is a part of the key. It is said that, through the power placed in the key, it is able to use enough offensive power to collapse the Digital World, but only on enemies that try to break through the doors.

(Source: Digimon Wiki)