I've been wondering who to turn into a Pony then it hit me
Roy Mustang
Mustang
Get it? XD

lol clever huh?
Don't answer that.
I bet someone else already did a Pony Fied Roy Mustang

Had a little trouble on what to use for the symbol then I thought he's called the Flame Alchemist so DUH! a flame!
Even drew the symbols on his ...horseshoe covers/gloves? But how would he shoot flames when he doesn't have fingers to snap? Click his hooves together? *shrugs*