Decoy Protagonist: Despite being set up by the opening and his introduction as the main hero of the story, there's no way he survives the first act.
Dropped a Bridge on Him: If Kay’l survives the boss fight with demon Telis he is unceremoniously shot and killed by a guard robot when you try and leave the sector.
Astaroth
Author Avatar: A rare accidental case, but he's one for Quantic Dream as a whole as he's the creator of Omikron in-universe.
Big Bad: At the core of everything, he's the main villain of the story.
Big Red Devil: Perhaps the most generic looking of all the demons in the game, but by far the most powerful.