Grab some celebratory cigars and stock up on junk food, because the Arrowverse family just got a little bit bigger. Welcome to “Watch the Arrowverse,” the weekly show where we take a look at some of the Easter eggs, important moments, and theories from all of CW’s DCTV superhero shows. On this episode, we’ll be looking at week 4 of “Supergirl”, “The Flash”, “Legends of Tomorrow” and “Arrow.” As we’ll be discussing the heroic details from all of those shows, we’re putting up the spoiler signal.