I am dissapointed

Because it’s not. The only similarities between KS and Chess Piece is that Jeoh and Yoonbum have similar appearance but have completely different personalities and both Manhwas being about psychological horror.

(Don't read the paragraph if you don't want, i'm just ranting)

also the milf is sangwoo's mom and the detective is sangwoo
they both have a uke with a "tragic life" which isn't even well executed here
and the seme captator, btw this seme makes no actual his actions aren't coherient and all of the first time he meets Jeoh his actions are kind of purely in plot convenience.

It also has the thing where seme can't fuck with Bum 2 cause he reminds him too much of that milf that looks likes sangwoo's mom.
and lastly this story might also end up in a ending where both of them die ;-;
and as the story goes on the more the Jeoh looks like Bum I mean they're not even tyring to hide it ¯_(ツ)_/¯

How is the milf like Sangwoos mom lol its a completely different relationship. I didnt even understand the part about the detective being Sangwoo lol?
Literally "tragic past" is one of the most commonly used tropes and he doesnt even really have a tragic past in the sense of family trauma? Its more of a shitty boring life and being forced into prostitution. I'd say it's pretty well executed, its just not what you want because its not yoonbum type tragic story lol
His actions arent coherent literally because he only does what the milf asks, he doesnt seem to take pleasure from killing etc like Sangwoo, so he doesnt have this type of motivation. Yeah, maybe his first actions are only for plot convenience, that would be valid criticism, but honestly I didnt really feel that. He wanted to kidnap the blond guy, he was following this organisation and he kidnaped the main chara by accident and doesnt know what to do about it.
Where did you even get the fucking part... It's not that he cant fuck him, he didnt want to at first and then when he did he imagined the milf because he wants to fuck her. He doesnt have a trauma about her or anything like that, he is codependent on her because he likes her...
You can literally say "they can both die" about anything...

110% agree with you. They’re just trying to compare KS and Chess Piece because apparently every psychological horror story has to relate to KS.