These 2 have such similar powers this battle had to be done. Mr.Freeze's suit gives him strength along with that gun, so he will be able to break
anything that Iceman tries to trap him with. Iceman won't be able to run away with his slides since Mr.Freeze can break them.
Mr.Freeze's gun won't hurt Iceman since he is already covered in ice. So this battle came down to other uses of their powers.
Mr.Freeze can only freeze things while Iceman can shape his ice. Iceman is known to shape his ice into weapons. The killing blow
is delivered by Iceman when he throws an ice spike or axe at Mr.Freeze's helmet. The thermal stresses on that thing are enormous and therefore it would shatter easily.
Letting the heat in will knock out Mr.Freeze as he either boils to death or just hyperventilates, whatever he does.
