Oh no! Your story's been infected with a classic horror trope! Who's your final girl? Are your characters going into the basement? Who gets possessed? How is everyone handling the jumpscares? (And any others, because I don't watch enough horror to know more 🤭)
I am going to answer for @bendingthelaws since in that story everyone is human and there is no magic whatsoever.
The final girl would be - Serena
The final guy would be - Karsten
Keegan and Declan would go into the basement - coming out might be a challenge
I think that Dimitri may already be possessed, but if not, I'm sure he'd welcome a demon to help him hurt those who threaten those he cares about.
Abby will be clinging to either Dimitri or Colton like a lemur. Aoife will be next to Colin, but more as his protector than a scared mouse. Serena will be between Keegan and Karsten, both protecting her, with Declan at her back as a big brother. Spencer will be wondering why the fuck he is there and wish he was back in the lab. Kalahan will be keeping Gabby near him and both will handle the jump scares fine, they are both trained killers, be it in different ways.
Constantin will be the villain, because, well he is a sick fuck.
Dominic will be Constantin's sidekick, naturally. He will die midway through.
There will be many ways of death, lots of deception, and lots of blood. At some point, the one killing them off will become known, but that does not mean they won't get caught off at times. There will be at least one explosion.