Greg responds...

1. Not that anyone was arguing with me over the choice, but I really wanted to cast Carl as M'gann's father. In part, as a tribute to his work on Justice League as J'onn J'onzz. But also cuz he's truly great, and I've been a fan of his going back all the way to Cagney & Lacey.

2. We held some auditions for someone who could play both Khalid AND Muhammed Nassour. And Khalid won the roles by being great at both.

3. We held auditions for someone who could play both Mary Bromfield and Child. Brandon and I had seen Erika perform an amazing stand-up routine about playing the violin and being frustrated by the ending of Game of Thrones, so she was one of the people we suggested as a possibility. And she killed it as both characters.

4. Brandon wanted to make Phantom Stranger Black, so he and Jamie Thomason and I began brainstorming who might be a good choice to play the role. I believe Jamie may have suggested D.B., and I was immediately enthusiastic based on his work in Lucifer and Buffy and 24 and other stuff that I've loved him in forever.