Actually, I think with a normal blast (fully powered), at 5d6 with slice can't cut through iron; not in one blast anyway. It'd have to at least do 40 pts of damage. In fact, I propose that there should be template or additional use of pressure, or something, cause Katara does the same type of attack against Hu in the swamp. Unless you're allowing blast stacking; or allowing pressure stacking some form of bypassing hardness.