The season finale of Titans wasn't really an ending to the first run of episodes on DC Universe, more setting up Dick Grayson's descent than wrapping up storylines. But it does set up Rachel's father Trigon to be a powerful foe to the group of young heroes.
In the pages of DC Comics, Trigon is a frightening demonic entity with a towering stature. But on Titans, he takes on a human form that's less than intimidating. Series showrunner Greg Walker explained why the show went this route for Raven's devilish dad, while also teasing a comic-accurate look in future episodes.
"I like the rendition of Trigon in the books, but I always thought it was more interesting to kind of play the human seductive side of evil that preys on your weaknesses rather than just preying on your fear," Walker said to Entertainment Weekly. "We thought of casting Seamus [Dever] and also giving him a character who was seductive would be more effective in understanding the nature of evil. That was the first choice. Whether or not we’ll see him take on that form when tested remains to seen, but I know as a fan that I would like to see it."
In a previous episode, Kory takes Dick Grayson and Donna Troy to her spaceship where they look at a projection of Trigon, who appears in his larger, demonic appearance. So it seems like he can transform if need be, among his other powers.
The new season of Titans will pay off of this thread, as Raven hopes to save Dick from her father's thrall with the help of Hawk and Dove. The first season ended with some dangling plot-threads, including Dove's vision of Rachel who beckoned her and Hawk to find the new Robin Jason Todd.
"I think Rachel’s gone to them because she senses where she’s going," Walker revealed. "Rachel is an empath and has a feeling where things are going, and so has reached out in order to stop what she fears is happening and what she’s right about happening. It’s all linked to a larger sense of trying to stop this demonic force from overtaking, essentially, the universe — as we know is the reason Kory was sent to stop Rachel, that this threat goes beyond Earth."
Every episode from the first season of Titans is now streaming on DC Universe. Season 2 is rumored to begin filming in early 2019.