I dont have time to read right now so I just skimed through, but I realised something.
Isak is with the MC because Noha killed someone he holds dear and being close to her will make him come out.
This is my theory in short i will elaborate more for those interested.
Its a bit long but stick with me.
The memory gap where in the last chapter she asks herself why did we go to the police station and where we also see Isak, im going to assume that after Noha killed her father (she continued to stay with him, was ok with him) he later also killed someone Isak holds dear, which lead to her going to the police station after realising he is a psycho and he's dangerous.
We see Isak at the police station and him saying to her its going to be okay.
Isaks monologue of how he believes in God because that would mean hell exists and people get their retribution, leads me to belive that he is hateful about the fact that Noha was able to walk free after having killed someone. What forties my hypothesis is that we saw someone taking the tulips out tof the trash can in anger, right after the sceen where Isak said Noha come out. He is luring Noha out.
Im going to assume that the title Im Dating A Psychopath comes either from Isak turning into one after Noha killed someone dear to him (assuming family since he has no pictures of them anywhere), or it comes from the MC being a psychopath and a mentally unstable person and how Isak has to date her to get what he wants.
I really dislike FLs character, how is she a secret agent with that brain in her head, how is she not dead yet, wtf.
And just because you are LOCO enough to risk you life, so you can prove a point, not everyone else is. I hate people who contradict themselves, and she is one of them.
Poor guy, he screwed himself over with this one
Luck. The answer is luck. Evidently she used to be less stupid according to her psych profile. Looks like she has been triggered too many times and developed a messiah complex.