inherited gamma mutation gives him secondary form with immeasurable strength, endurance, leaping ability, and resistance to all forms of physical injury, immunity to volcanic heat, inherited Oldstrong Shadow power draws on geological energy, further boosting strength and power, providing psychometric hyper-sensitivity to vibration, and ability to manipulate seismic activity, carries massive sword
Dark Avenger. Appointed membership by Norman Osborn in New Avengers (2nd series) #18. "Dark Avengers" not recognized by Avengers founders or general membership. Also undercover for Captain America, but uncertain if he received genuine Avengers status as a result.
Skaar's gamma power is presently inhibited following Hulk (3rd series) #7.