Name: Melting Point
Description: Allows the user to be able to heat up their hands enough to melt through anything they touch. They can also make most liquids evaporate almost instantly, allowing them to create a cover of steam. In order to be able to heat their hands enough, they also have a high level of heat resistance.
Weaknesses: They can't control what they melt when their hands are hot, meaning they have to cool their hands in order to grab something. It takes about a minute for their hands to heat up, & it always affects both hands, meaning they can't heat up only one hand.
Position: Villain
Sample Character: A sadistic girl who enjoys torturing her victims in order to gain information gets captured by the heroes, only to be saved by the League. In order to repay the debt she believes she owes to them, she joins them.
Extra Info: This was suggested by MatthewMumford. I hope you like the weaknesses I came up with & I hope I didn't change it too much from what you had in mind.