The title "Promise" refers to more than just the wedding vows. It’s a web of conflicting oaths:
Here, we witness the "Luthor" in Lex. Threatened by Dr. Langston over the truth behind Lana’s pregnancy, Lex resorts to cold-blooded murder in the church crypt, proving he will do anything to keep his "prize." [S5E3] Promise
This move solidified Lionel’s status as the show’s most complex figure—is he acting to protect Clark’s secret, or is he simply the "Magnificent Bastard" ensuring his family’s power? KryptonSite notes that this episode marked the character's return to his full, manipulative glory. The title "Promise" refers to more than just
Perhaps the most pivotal, we see Lana finally discover Clark's secret on her own. She watches him use his powers to save Chloe, leading to a moment of pure joy that is immediately snuffed out by a terrifying ultimatum. The "Magnificent Bastard" Returns Langston over the truth behind Lana’s pregnancy, Lex