Just a few words about this one, don't let the stats fool you, the card is actually 2 costed, not 4.
Now to fill the 200 words required to post this : a card that's impossible to play for most heroes, hard for the rest, with the exception of Iron Man (loves to get aerial anyway) AND, of course, Thor, who could get a second 3 ATK from this, plus control over the main scheme... (OK, I'll have to try something with it now). Mjolnir making you aerial might be useful after all (same goes for Agile Flight and Dive Bomb).