In the weekly Quentin and Damien Darhk secret meeting scene (QDDSMS? No.) we have Captain Lance going to Darhk in search of some advice, as he knows about the latter's time with the League of Assassins and the fact he has experience of the Lazarus Pit. Darhk, however, tells him something he doesn't really want to hear. That it's a miracle she even came back, that it's not really his daughter, and the best thing to do is kill her again. What's surprising about this, though, is that he gives this advice "father to father" and makes a reference to his daughter. Who could be the offspring of such an evil, mystical, genius-of-a-villain? It's likely not to be just an offhand reference, making me think we will meet his daughter at some point this year. Unless we have already? Say, someone close to Oliver. An OG member of Team Arrow. Stranger things have happened, though it's very much in the crazy fan theory pile at the moment.