[SPOILERS for Legends of Tomorrow 'Invasion!' ahead]
Ever since it was announced Supergirl would make the jump from CBS to The CW, fans have wondered when she would appear on screen along with fellow DC TV heroes from Arrow, The Flash, and Legends of Tomorrow. The CW president Mark Pedowitz was quick to assure fans there would be a massive four-show crossover, and that three-hour event completed tonight with the debut of Legends of Tomorrow's latest episode, 'Invasion!'
The CW kicked off the four-show crossover on Monday of this week with a short sequence at the end of Supergirl's episode, 'Medusa', but the action truly began with The Flash on Tuesday, continued through Arrow on Wednesday and concluded in Legends of Tomorrow. The last episode saw the heroes pull together and battle a horde of aliens -- from a race known as the Dominators -- bent on destroying metahumans. Additionally, the crossover event featured a number of easter eggs, pop culture references, and in jokes to amp up the entertainment for fans.
One such in joke arrives in the final moments of Legends of Tomorrow's 'Invasion!' when Ray Palmer, played by Brandon Routh, mentions that Kara Danvers aka Supergirl (Melissa Benoist) looks a lot like his cousin. Though fans may hope this is an indication The CW's Arrowverse will introduce Earth-1 Kara Zor-El, Legends of Tomorrow executive producer Marc Guggenheim revealed to ComicBook it was a joke referencing Routh's turn as the titular superhero in Superman Returns:
In respect to the cousin line, basically it's sort of like [what] we did last year on Legends. We did the prison break and I said to the writers, 'If we don't make a Prison Break joke here with Wentworth, we're not doing our jobs.’ If we have Brandon and Melissa share the screen and we don't make some sort of joke like that, we're not doing our jobs. The truth is, that joke existed on Arrow originally. Then, a certain scene got cut so I moved it over to Legends. I just kept moving it back and forth. I'm like, 'I'm getting it in one of these episodes.’
Of course, the nod to Routh's past work is sure to please many fans since, as Guggenheim referenced in regard to Prison Break, The CW's Arrowverse is no stranger to offering viewers meta in jokes about its stars' previous work. Still, with Supergirl remaining on Earth-38 (for now) but confirmed to exist within the multiverse, fans are likely curious about her doppelganger from Earth-1 -- especially if that doppelganger could mean the introduction of Power Girl.
That said, since The CW's DC TV series have only just finished airing their massive crossover for the season, it remains to be seen what else the shows have in store for fans. Certainly, there's the Supergirl and The Flash musical crossover, but additional future crossover events remain a mystery for now. However, no matter what those crossovers entail, fans can be sure to expect even more easter eggs, pop culture references, and in jokes in the vein of Legends of Tomorrow's reference to Superman Returns.
Legends of Tomorrow continues Thursday, December 8 with ‘The Chicago Way’ at 8pm on The CW.