generate thermochemical energy as a blast field, which can act as propulsion, bio-kinetic blasts, a protective force shield, and a containment field around his opponent, or absorb kinetic energy to create shockwaves or supercharge the force behind his punches
According to Jean Grey in Uncanny X-Men (1st series) #287 and Onslaught: X-Men, the Blue and Gold Strike Forces were still active at the time Onslaught struck, meaning that Cannonball should have been a member of one team or the other. Which one was never clarified.
Since the extermination of most remaining Externals back in 1996, Cannonball's status as an immortal has been virtually ignored. A brief reference was made to it in passing from New X-Men (2nd series) #32, but from that it wasn't clear whether Sam was still considered a High Lord or not.