Lucifer deliberately mispronounces Constantine's name with what is actually the correct pronunciation of his name in the original comics, a shout-out to fans who were annoyed it was changed for both the television and film adaptations of the character.
Cress Williams was immediately starstruck when he stepped onto the set of the Arrowverse's "Crisis on Infinite Earths" saga for the first time. "It's like going to a new school," said Williams, who took a break from shooting Black Lightning (2018) in Atlanta to spend a week working on the crossover in Vancouver. "I was just really overwhelmed at the pure number of people, and all of these super suits. I was working with the Flash, two Supermen, most of the cast of The Flash, and some Arrow people. It was just a real hodgepodge, a full room."
Ashley Scott reprises her role as Huntress from Birds of Prey (2002), which also starred Rachel Skarsten, who now plays Alice on Batwoman (2019).
In the comics, Ryan Choi was a student of Ray Palmer and his successor as the Atom.
With Cress Williams flying between the two filming locations on the weekends to maximize his availability, Black Lightning's writing staff reduced his role in several episodes to better accommodate his involvement.