Looking at Iceman here:


If he Hypersonics, would he leave two barrier markers?

Hypersonic is two moves and the the power does say 'Whenever Iceman moves, after resolution of each move, you may immediately place a Blocking terrain marker in a square he moved through', I'd say yes, he would leave two barrier markers.

Nice find, that makes him even better.

You can get him to 3 squares of barrier if you take the pushing damage and go from click 3 to click 4 and then Side-Step.