Though the virus was meant to suppress superpowers in violent crimes, it removed all but the most invulnerable's powers in the city and gave superpowers to otherwise powerless people.
A clone of Supergirl named Galatea would factor into a number of episodes and demonstrate the animated Supergirl's powerful potential, though Supergirl would manage to eke out a win.
Joseph Jones Justice League America 50 Deceased in Justice League Quarterly 16.