I unknowingly made this comment long I’m so sorry.
The ones that I’m recommending aren’t totally similar, but they all have that same vibe ifykwim… angsty. ( ̄∇ ̄") all the art of the ones I’ve listed are all 1000/10s.
1.) Tears on a withered flower. The ML hides his identity from the FL, who is in a miserable relationship with her divorced husband. ML is pretty much a ‘bad, gangster boss’ guy but pretends to be some adolescent teen who keeps getting into fights. The FL is heartbroken and doesn’t want to give herself away so quickly but she’s very naive and keeps falling for his ploys. I have no clue why the ML likes her. But so far I want to infer it’s because he likes challenges, when things become easy he gets bored and tosses it.
2.) Merry Psycho. This one FL is happily married and blind. But one day her husband (the ML) ups and disappears and her sight comes back. She goes full yandere mode trying to find him, literally doing anything and everything to even find a trace of him. Oh baby he does not want to be found, should’ve seen his face when he caught wind of her.
3.) There’s a rat in our house (one of my personal favs). There are no killers in this one, just to point that out. FL is pretty monotonous when it comes to most things, but she finds the ML on a snowy night and takes him in out of… mostly pity. But eventually the ML begins to idolize her as his world and the FL can’t really give him the love he wants, thus cue the angst bc he’s a little obsessive and she’s very emotionally crippled. They’re both broken.
4.) Villain, I’ll Do Everything Except Marriage for You!. As you can tell from the title it’s a rofan, not a modern romance, but I think the vibe is swinging in this direction. ML is renowned as a killer in high society and the FL is absolutely terrified of him. She literally shakes at the mention of his name. Her shitty family ends up getting them engaged. ML fakes his identity when they first meet and he learns she doesn’t want to marry him, so he continues to fool her. They’re even get engaged with his fake identity in order for him to marry her.

i need to read other manhwas that are similar to this one