I dont remember the beginning but i remember bits in the middle part and the ending. In the middle part, Monster/Demons were roaming around the city and destroying stuffs they see, like what typical monsters do. Dont know where these monsters came from but some people started to have some sort of bulging dried scars or marks or wound and later they would turn into Real demons/monsters but can transform back(?) . There is this girl (Maybe High school?) She started to have these marks on her upper arm and shoulder in a shape of (from what i remember but still not sure) a spiral. Then She later transformed into a demon and there was another demon and they fought in an open area which i’m guessing is the rooftop. Another was a man and his girlfriend was running around the city. The man can also turn into a demon but not an ordinary demon, he was like, special. So a strong demon, took or kidnapped or something his girlfriend and use her a a bait to lure him. He beheaded the girlfriend and placed her head on top of a table(?) which made the guy angry and they fought. The guy won and in the ending, It just shows the some kind of fire all around the place and in the middle of the screen was the guy’s girlfriend’s head sitting in the table looking back at the screen

I’m about 70% sure that this is a movie because i watched it from a dvd player and I dont watch series on a dvd. The cd is either missing or was recycled. Then I’m about 60% sure that that was a Japanese movie cuz i watched it after I watched Kamen rider 555 Movie paradise lost. It had the similar feeling to the Kamen Rider movie. I watched that movie when I was like grade 4 or 5 but now i’m in first year college.(btw our grading system is NKP-> Grade1-6 -> highschool 1-4 -> College 1-4.) So that was probably 6-7 years ago. the movie was 2008 or lower