Antimatter Mimicry – The being is composed of antimatter or is a containment unit for antimatter which can be used for various effects.
In Justice League of America V1 #47, the Anti-Matter Man (DC) is able to take on the Justice League of America and the Justice Society of America at the same time.
The Anti-Monitor (DC) can take on superheroes from not just two but several Earths (Crisis on Infinite Earths #12)!
The Blue Marvel (Marvel) is one of the most powerful heroes in the Marvel universe (OHOTMU A – Z Update #1) and uses antimatter as the basis of his superpowers.
Anti-Man – Fourth Doctor Sourcebook