Quit in X-Men, vol. 1 #94 (1975) after only one mission, but remained an ally for years afterward.
Confirmed depowered in New Avengers (2006), but regained his powers when he was transformed into Apocalypse's Horseman Famine. Partially freed from Apocalypse's influence by Mister Sinister.
Currently seen in Uncanny Avengers.
Powers: Generation of nuclear fire, flight by jet propulsion, absorption of and immunity to various kinds of radiation.