Immortal Breaker (armament)

The Immortal Breaker is a weapon capable of harming immortal beings.

Gallia Sphyra: Outseal is an Immortal Breaker. It is a Legacy Weapon designed by humans during the Prime Field War for use against the Prime Fields. As a result, it was given the ability to harm immortals.

Mai Natsume used Outseal in BlazBlue: Variable Heart against Fuzzy, which harmed him, as he is a vampire and thus immortal.