She also battled her other half, Red Daughter, after discovering that Lex (who’s quite the tech genius himself and not afraid to use it to reach any dastardly goal) had been harboring and training her as a part of his plan to harness alien energy to destroy Superman’s new home of Argo City.
Season 4 saw Melissa Benoist’s Supergirl fighting multiple villains, including Sam Witwer’s Agent Liberty and, later, the diabolical Lex Luthor, played by Jon Cryer.