With Arrow, Flash and Legends Of Tomorrow already cemented in at The CW, it's learned the planned mega crossover with Supergirl will see Melissa Benoist's Kara Danvers on all four shows.
"It’s an external threat from outside the shows that will involve Supergirl coming over to The Flash, then Arrow then Legends of Tomorrow," Guggenheim explains, reports Slashfilm, with the big bad not made known. “I don’t like to oversell. She is going to be coming over but we’re not going to do a full on Supergirl crossover episode. I don’t want to give you the wrong impression.”
Guggenheim also talked about the Justice Society coming to Legends of Tomorrow where it's learned it's not going to be a super team-up.
"It’s all going to kick off with an epic battle between the Justice Society and the Legends," Guggenheim said. "It’s required that every time there’s more than one superhero in any place at any given time, they have to fight. We’re honoring that rule and that tradition straight out of the gate."
Arrow, The Flash, DC's Legends Of Tomorrow and Supergirl return to The CW in October.