The CW has released the first image of Jon Cryer's (Two and a Half Men) turn as Lex Luthor in an upcoming episode of Supergirl. The episode, "O Brother Where Art Thou?" will debut in March, and will see Lex reaching out from prison to enlist the help of Lena (Katie McGrath), where he will do anything to get her on his side -- "even if that means leveraging the life of one of her friends." We don't know much more about what the episode will hold or what form the villain's evil will take, but the Arrow-…