Killer Frost

If the Suicide Squad has Diablo, the Harley Quinn spin-off should have Killer Frost. Able to absorb heat from all sources and transform it into waves of cold, she would be a nice addition – especially since she also has superpowers. She can create projectiles, she can create hard walls of ice, and she can freeze living matter just by touching it.

Killer Frost may not be such a well-known character. And she may not have as interesting a history as other characters on this list. But this doesn’t mean at all that she wouldn’t contribute to the success of a movie.

Plus, she would be the character who proves how real a threat is. You know what I mean.