Black Scorpion (1995)

Justice has a nasty sting.

Darcy is a cop who is also a supehero named Black Scorpion at night who kicks and beats evildoers to a pulp. She soon catches wind of an asthmatic mad scientist who plans on tainting the city's air supply with a toxin. Only Darcy in her superhero garb can stop him with the assistance of a petty thief named Argyle.