Pyro is an X-Men villain, part of the Brotherhood of Mutants, but he'd still make an interesting lead character in his own movie (also, technically, he joined the group in Ultimate X-Men). His powers are visually stunning: he has the power to control/direct fire, though he cannot create it on his own. That could make for some very slick action scenes. His portrayal in the X-Men film series by Aaron Standford (in X2 and X-Men: Last Stand) was solid, but left lots of room for potential growth. Basically, this is a character that a talented writer/director could take and really run with. With D.C. considering a Sinister Six movie, maybe it's time a villain or two in the X-Men universe got a headlining role of their own.