Because people often judge things superficially without delving deeper or understanding their causes. In reality, in KML Grayson just seems like an annoying playboy because that's Keith's view of him. Still in the same manhwa, Yeonwoo's view of him is of an imposing and intimidating playboy. In KMIYC, he seems perverse because that's Chase/Josh's view of him. For Ash, Grayson is a psychopath who could kill his love or other people at any moment. Therefore, Grayson is judged from various perspectives and framed according to each character's perception, but in Desire you get to see HIS point of view and Dane's. And thus you finally understand why he makes such strange decisions in the eyes of almost everyone.
this!!! where's the like button for replies i can smash??? this is why i'm so glad we get to see a perspective that is actually Grayson's. not that i approve what he did to his brother's head but i was always open to the idea that there's more to these twisted characters and it's always worth reading. plus for me personally i get to see Dane put Grayson in his place. Dane had always intrigued me since 'kiss me liar' so i was shocked when i later learned that he and Grayson are a thing coz again, perspectives. in kml and kmiyc, Grayson was that character that irked me but we never really got his own pov..... tho apparently from bookreader comments here he's just the way he is lol but still, i love that we got his and Dane's story

I’m sorry, but this can’t be the same Grayson from Chace ‘s story like that Grayson was evil…. Like this Grayson looks kind of dumb and adorable like why am I low-key fucking with it