Atoman was a member of the Seven Sentinels. He enjoyed celebrity status. When M'rrgla Qualtz was arrested, he tried to free here by hiring a lawyer. It was reveal that he and the other Sentinels faked all of their famous battles and were actually a pedophile ring using their sidekicks are sex slaves. He was able to stay safe from the law by hiding in his "Fall Out Shelter" (which is impossible to break into). However, Joe Pi pointed that if tried to break out the cops would sucks his powers his away and send him to jail, but if he stayed he would be stuck. However, he "accidently" mentioned Atoman's Hall of Sounds. So, this gave Atoman the idea to use Violet Soundwaves to kill himself rather than "spend the next twenty years bending over to Doctor Dread or Antimax". which he did.
Atoman's powers are never shown in action except for enchanced hearing. However, it's implied he is extremely powerful. It's also mentioned that he has a lifespan of 300 years. Also, soundwaves can effect him: blue soundwaves temporarily remove his powers, cyan permentally saps him of his powers and violet kills him.