A character fights in a skintight leotard or, more generally, a swimsuit-esque one piece. Pretty common as a Super Hero trope, especially during its Golden Age, where the costume originated as gymnasts' and circus performers' garb and since then it isn't always used for Fanservice (strongmen and wrestlers were as likely to wear it as acrobats, and so you'll still see the occasional hulking bruiser wearing it to show off their massive musculature).
Leotard of Power has been suggested to play 2 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.