With our powers combined~

Sometimes it's hard to determine a person's element by their personality alone -- bending isn't really an adjective as it is a verb, it's defines how you do things instead of how you are -- but if Mike wasn't the Avatar, he'd obviously be an airbender no questions asked.

So why earth? Well, for one thing it's the one that follows water (Korra), and for another thing I based it off his parents; his dad's got that stubborn, stand-your-ground earthbendy attitude. And, hey, since Mike is the Avatar in this AU...I get to cheat a little