Zero, otherwise known as (an instance of) Boyfriend or BF, is an ex-singer turned mercenary. Zero is a bit introverted, and holds a dislike towards law enforcement in general. However, he holds an even greater dislike towards yandere infectees.

Zero's body holds two inhabitants -- mainly The Corruption and Nightmare BF.

Zero has a power that goes by the name of Echo. It allows him to temporarily copy any power that he is able to understand.