Chamber's powers and abilities
Psionic Biokinesis
Chamber was a mutant who was naturally composed of pure psionic energy. In truth his physical body was just a shell for what he truly was. The initial emergence of his powers blew a hole in his chest and lower face, completely incinerating most of his internal organs. Because of this, Chamber no longer needed to eat, drink, or breathe. Oddly enough, Chamber's blood did continue to flow through his extremities, as if propelled by a churning engine of psionic flame itself. However, he was sustained solely by the psionic flame that raged within his body. If it were somehow snuffed out, he would most likely have died. But then, he might argue that he already died once, and came back, so his reaction to a disruption of his mutant abilities may still have been unclear. As his flames were actually psionic in nature, and didn't rely on some form of fuel to continue to burn, they didn't seem to be affected by conditions that would be adverse to actual flame (ie. lack of oxygen, water, etc.)
Biokinetic Flame
Chamber constantly created and unleashed psionic charges of energy that could strike with concussive force, act as generic flame, or cause inanimate objects to explode violently, by forcefully disrupting molecular bonds. It seemed Jono couldn't actively affect molecules containing Carbon in that same explosive manner, but those molecules were still very vulnerable to a direct hit with his biokinetic flame. It was shown that if chamber realized his full potential he could in fact rebuild his broken body or use his blasts in a number of ways, such as flying. Though lack of any real control over his power prevented that.
Projection Telepathy
Basically, he was a radio that could send out signals, but not receive them. Chamber couldn't read minds, probe thoughts, or see things that lied outside his line of sight. He could, however, use his abilities to 'speak' inside the minds of those near him. He could also create psionic illusions. For the most part, these projections were unfocused, and anyone within physical hearing (or viewing) range would be affected. Chamber was beginning to learn limited control over this, however, and was sometimes able to limit who heard and saw what he was projecting. Physical obstructions didn't affect these projections as they would real sounds and images. For instance, a person on the opposite side of a soundproof wall would still be able to hear him, as long as she was close enough.
Psionic Blasts
He could project psionic force bolts which had no physical effects but which could affect a victim's mind so as to cause the victim pain or unconsciousness and could even kill an adversary.
It was once suggested that Starsmore's physical form disintegrated a little more with each use of his power. The full range, extent, and nature of Starsmore's psychic abilities are unrevealed.
Because of the large infusion of Apocalypse's blood, Jonothon may or may not have the other powers of Clan Akkaba such as enhanced strength and durability, as well as the ability to reshape his limbs into weapons.
Sonic powers (possibly formerly)
Jonothon, as Decibel, uses advanced technology create to sound-based energy powers of an unknown degree. He's been shown flying, creating individual force fields around multiple targets (four shown), creating energy constructs (a giant wall and a back hoe) as well as two different types of energy blasts, one from his mouth and another from his hands.