The Arrowverse's upcoming Crisis on Infinite Earths event will fulfill the comic book story's original goal. The Arrowverse has been setting up Crisis on Infinite Earths ever since The Flash's season 1 premiere, and it promises to redefine The CW's slate. Shows will live, shows will die, and the Arrowverse will never be the same again.
The DCTV event is inspired by a classic comic book miniseries by Marv Wolfman and George Pérez, which kicked off in 1985. It saw the Anti-Monitor begin destroying realities with a wave of antimatter, with the greatest heroes from across the Multiverse assembling to confront the threat. Despite surprisingly limited marketing, Crisis on Infinite Earths was a bestseller; it's generally credited as having saved DC Comics, a company that had been struggling at the time. Many of the series' central events - such as Barry Allen's sacrifice and Supergirl's death - have established their place in comic book history.
The comic book Crisis really had three goals - and the Arrowverse event looks set to hit the exact same targets. Firstly, in the comics, Crisis was envisioned as a celebration of everything DC had ever done. Wolfman and Pérez crafted a story that incorporated countless different versions of DC heroes, from comic book genres as esoteric as sci-fi and Westerns. In exactly the same way, the Arrowverse's Crisis appears to be a celebration of decades' worth of DCTV shows. Shows like Birds of Prey and Smallville are being incorporated into the Arrowverse's Multiverse, while the event will see a number of classic actors return to the DC fold; their numbers include Kevin Conroy (Batman: The Animated Series) and Burt Ward (Robin in the 1960s Batman series).
Marv Wolfman was originally inspired to write Crisis on Infinite Earth when he received confused fan-mail from a reader who was trying to understand the comic book publisher's continuity. Wolfman realized that decades of relaunches had left the continuity a mess, and he resolved to deal with the problem once and for all by penning a tale of Multiversal destruction. The scale was grander than anything DC had ever published before, and it was seen as a risk; but Wolfman successfully persuaded editors that it was a necessary step to straighten the continuity out, effectively relaunch the entire comic book range, and create new opportunities for team-ups and crossovers.
Again, the Arrowverse's Crisis on Infinite Earths looks set to fulfill the same kind of purposes. It's generally believed that the end-goal of Crisis is bringing the different Arrowverse worlds together, meaning Supergirl's Earth will be merged with Arrow's, creating new crossover and team-up opportunities. The story will mark the end of the classic Arrowverse, with Stephen Amell bowing out as Oliver Queen, but will relaunch it in a new incarnation that could include brand new shows starring the Canaries and Tyler Hoechlin's Superman. There's a perfect symmetry to this; just as in the comics, Crisis on Infinite Earths celebrates everything that has been done to date - but also marks a new beginning.