The first three episodes alone delivered some major ones, ranging from DC Universe’s Titans turning up to Lucifer’s Lucifer lending a hand to Constantine, but the DCEU connection in the Arrow leg of the crossover may be the biggest: Ezra Miller, a.k.a the DCEU Barry Allen/Flash of Batman v.
The Arrow-verse has finally returned in 2020 with the final episodes of the five-show “Crisis on Infinite Earths” crossover, and it didn’t waste any time in delivering another huge DC cameo.
Superman, Justice League, and Suicide Squad, made an appearance.