Back in the international X-Men days, Sunfire was the representative for the Continent of Asia. He got his powers because his parents were irradiated by the atom bomb when it blew up Hiroshima.
Or it was back in the day. He was never part of the X-men officially, having refused membership. He's sort of a side character who pops up every now and then, particularly if something's happening in Japan. But he's one of the few Asian Superheroes whose super power isn't martial arts, so awesome.
I find it surprising that they decided he should be one of the 3.75" figures. They never even made a Marvel Legend of this costume. (Opting for the Age of Apocalypse costume.) But here he is, and here I bought him.