was the biggest Arrowverse crossover of its time ... but the nuts and bolts is that Rosso is planning to break Wally West/Kid Flash (Keiynan Lonsdale) and use him to access the multiverse so ...

There once was a time when the Arrowverse was the best live-action franchise DC had going for it, but it's a long-gone era ...

and shows like The Flash and Legends of Tomorrow still have fans calling for more, so it's not too wild to foresee a day where fans with Max subscriptions could one day get an Arrowverse movie ...