Insane & Possessive Lover

I have never been as jealous of a female lead, for getting to exist in a fictional world with a man, as I am of this woman. He is everything. He is perfect. He is absolutely, completely obsessed and will go to any length necessary for her. He’s very respectful but also an obsessed stalker and does some bad things for her.
Not insane or the most intense ML on this list tho.

This one is slightly a psychological thriller type. No one has ever loved him and he has been extremely outcasted by society and abused. She was young and lost her parents and was also outcasted. She’s a bit scared of what he’s capable of and he’s completely obsessed with her, the only one who’s ever showed any kind of affection. They basically start living together in an underground bunker because of their abusive guardians

Don’t be fooled by the cover it’s not a love triangle bc the other guy is barely in the story. ML kidnaps him and makes him play the characters in the book he wrote that love each other. 100% psychological thriller and the ending (thankfully) didn’t disappoint. He’s so insane it’s amazing.

So most of these characters are kind of crazy. Mains are alright but the VERY BEST is the unhinged gangster and the main guy’s bastard brother. I love him so much you guys don’t understand. He’s unhinged and does not care what anyone thinks of him. The only person that exists in his world is his lover. Their story is WAY too short
This character inspired this list.

Read it twice but that was a while back. He starts out as the super crazy toxic one but then it shifts more to her as he starts to get better. During their story they both go crazy and its not romantic at first until it is, and my god when they are at peak codependent insanity? *chef's kiss* Amazing
They both regain their sanity and mental health by the end which I have mixed feelings about but overall fantastic.

ML is willing to kill and die for him. Fell in love when they were young in school and became obsessed and played the long game for YEARS to have him. He is extreme but doesn’t "let himself go off the deep end" and kidnap him or anything to keep him when they are separated in high school unfortu-
I think its runs a BIT too long but its really good.

This one is NOT romantic. It’s just really dark. I’m just warning you guys. Mentally prepare yourselves for the darkness before jumping in. EXTREME Sadist and obsessed/ brainwashes him. You've been warned lol