VIDEO : 'Supergirl' Will Explore Lex Luthor's Relationships With Lena and Kara

Lex Luthor's arrival in National City on tonight's Supergirl is going to be a major game-changer for The CW series. While the iconic villain is getting out of prison due to his failing health, a weakened body likely won't change Lex's wicked heart which may present some real challenges -- especially when it comes to ...