Spoiler!
And... Ilay's treatment of Tae only gets worst from there... Believe me when I say that Ilay is one of the most vile Red Flag tops main ML (just see Gable's POV) to have ever graced BL Manhwas. Worst than Choi Yule, Cha Wookyung, Park Taesung, Woo Shinje, Kim Hyunje, Park Nakwon... but if you understand his character, how his mind works, his actions makes so much sense. Which is why I like his character so much.
Even when Passion ended, I couldn't see them as "lovers". I can't see their relationship as "romantic" or "intimate" but at the same time... it makes so much sense given the kind of personalities Ilay and Tae have... even during the sequel, Diasphonic Symphonia, I kind had doubts to the legitimacy of their "love", not just bec of Ilay's Psychopathy but also bec Tae is just absolutely terrified and traumatized of Ilay...
But... over time... little by little... Ilay does learn how to be slightly less inhuman. And their relationship does gain a bit of normalcy.
But that's why I like Passion so much. Like The Beast Must Die, it portrays a pseudo-realistic depiction of how a relationship with a "Psychopath" like Ilay would work.