Overall I think this is a good read for a short thriller. If you are considering revising, I'd advise you clarifying the location and scene descriptions and improving on your dialogue. I think the ending was good, leaving a suspense on the dead bodies. A part of me wondered if the dead bodies were coworkers of Jackie and Chuck's. The ending left me with more questions than answers, like was Scott involved? These are good because it leaves me excited to see the next film you know.
Overall I would rate your screenplay a 8.5/10. As far as structure, everything is on point, the action, character, dialogue, etc. I also liked how you did subtle things like italicizing to show highlight subtiltles. The script definitely flows well and with the main characters and side characters I believe everyone gets equal screentime here. One thing I might add, is that considering Erik is one of the main characters its good to see him drive the plot because that makes him dynamic instead of flat and letting things just occur to him. The conflict between his sister kidnapper and himself is geninuely felt although it can be cliche with the whole I will find you if it's the last thing on earth. Lastly, the script reads well however like I said before I was having a hard time reading it with some of the obscure locations and descriptions you said. If you tweak some of those errors in your scripts and making it more "readable" it might be a 9/10. Thank you for letting me read the script. God bless.
My overall thoughts is it's a great screenplay that explores the supernatural: demons, zombies, three headed werewolves, etc. I do think you can improve on your character descriptions. For example the Iycan Cerberus; I had no idea what or who that was, so I had to look it up. With a simple character description of the beast, I would've known it was a three headed wolf. Also I do think that SVF shouldn't be skinny, but be built because he kills monsters thrice his size. Besides my nitpicks, I do think you've did a good job rewriting the story. I think this story reflects real life, like how every day SVF is thrust into a new battle, is like how every day us as humans go through battles as well. Although it may not be against zombies, wolves, or S.W.A.T. teams, we still go through battles. Your demonology was bibically inaccurate but it's okay because this is your story and your idea on how demons are portrayed. Although I do believe SVF's need to be angry and low to fully transform is cliche considering figures like Hulk, etc. Overall great screenplay.
Through the trials and tribulations of growing up in the south side of Chicago, Edris Johnson becomes born again as a Christian.