The Tower of Oblivion

At the higher levels of the tower you'll have to customize your squad for each specific level. You'll want to know exactly how much damage your damage dealers can take and still barely be alive enough to get one last round of attacks off. You'll have to know which enemies you can kill by swapping out your guys in order to do enough damage to take the needed targets out. All of these things are level dependent so you're going to have to analyze the level, your own heroes at your disposal, and calculate the best attack from that information.