This is the main reason I suggested about "Auras of __" that way they can still keep their terrain only skills, perhaps like with monks getting a little animation when turning it on or have it persist like Darkside. On Aura of Fire have flames surround your feet, water have bubbles and so on, seeing as we can't really restrict a class to 1 element otherwise in Alex you'd be stuck with "metal" all the time and I don't think Toph will be our teacher here. (Points to whoever gets that)
