The concept of this series seems really cool and I definitely enjoyed the first episode. I thought the demon looked a lot like the Night King from GOT. Lol
As for the cast, I'm so used to seeing Mike Colter as either a drug kingpin from the Good Wife, or a butt kicker from Luke Cage, I will have to adjust to him as a priest in training. Michael Emerson, an alumni of Lost and POI fits perfectly as the calculating and eerie Townsend. Don't know much about Katja Herbers but I thought she fit in very well.
IMO, unless the creators screw it up, I think this show has a solid shot at a second season. Let's hope so.