Passion has 2 other novels dyamphonic symphonia and suite. Suite in particular has a lot more maturity from Ilay's side and character devlopment. Again not justifying him being a rapist or piece of shit. But I think i prefer how the change isnt sudden, that he falls in love with tae and does a 360 like in codename anastasia or roses and champagne. His devlopment therefore feels a lot more logical. After being in years of relationship with tae do we see gradual changes in his habbits. Since its been established hes a psychopath, i think changing his personality completely wld have been way worse because then his actions are just justified under "he loved him" "he did it for his affection" etc or that he had childhood trauma.
I'll be honest, I don't know what people see in this. I know it has a huge following with very devoted fans, but it's 142 chapters with no character development and a rape finale. Which apparently wins Taeui over to finally stay around. Iilay is such a one-dimensional flat character too. The art is great but I don't know how this won over such a cult following.