One of the more complicated issues (of surely many) regarding the crossover is that it ends up falling during Arrow‘s 100th episode.
As for the massive crossover, it was revealed that it would begin on The Flash, and run through the 100th episode of Arrow, before concluding on Legends of Tomorrow.
It was later announced that Kara Danvers and Barry Allen would also join together in a musical outing.
Further, Guggenheim added, “I haven’t seen the episode all cut together yet, but it has some incredibly iconic moments,” he said.