2) Creating The Legends – Arrow/The Flash
By the following season, Arrow and The Flash were both running smoothly, so it was time to use them both to launch another DC series, Legends of Tomorrow. The amount of screen time it took for both shows to introduce Legends’ ensemble cast was a bit excessive, but the crossover two-parter which basically acted as a backdoor pilot was thankfully terrific.
With immortal villain Vandal Savage on the loose, Green Arrow and The Flash join forces once again – but this time Black Canary, Speedy, Spartan and Hawkgirl and Hawkman get in on the game, as well. Not to mention Malcolm Merlyn (though whose side is he really on?).
As well as all these costumed sorts fighting together, the episodes “Legends of Today” and “Legends of Yesterday” have a very fluid narrative. Two-part crossovers like this can often feel disjointed, but the inclusiveness of the Arrowverse means that both episodes feel like part of the same show.