Gemini Man

Guarantee a third one is going to show up at the end.
Actually, once they join forces to take down the evil organization, they’ll infiltrate the HQ and take down the main bad guy. As they are escaping together they stumble upon a lab filled with super soldier fetuses. Young Will insists they leave, but Old Will says he has to go; to lead the life he should have had. Young Will escapes and Old Will stays behind to blow up the evil HQ and himself.