
LOL, I FORGET THE STORY. PLS SOMEONE REMIND ME.

Spoiler
Choi kanggo: has a sensible nose, he can smell feelings, so he can smell Kamin liking him and fell in love with him.
Kamin: loves sprout man, saw kanggo disguised as sprout man in the school festival an fell in love with him
Kamin grandma: hates Kamin, blames him and his mom of killing his son (Kamin father)
Kamin mother: left Kamin with his grandma because she didn't have money or time to care for him
Kanggo mother: is the voice actress of the hero companion of sprout man, Kamin idolizes her.
Kanggo sister: care a lot for his sensible brother, she makes doujinshi and fanarts of sprout man, Kamin idolizes her too
Kanggo uncle: is gay and going out his his friend
Green haired friend: kanggo rival
Other friend: Kamin friend, likes sprout man too

I just can't like Ilay (seme). He is hot but annoying( ̄へ ̄)....

More than annoying I think he's more of a totally and literally crazy individual.
He is an extremely intelligent man, even from a social point of view, as incredible as it may seem. As Taeui has pointed out several times and as we could also see in some circumstances, Ilay actually has good manners (when he wants to lol), for example he has shown respect when faced with higher ranking people within the organization and the fact that he didn't kill any of his students once he became an instructor.
What he seems to lack is the emotional part, a lack of awareness of what is right and wrong as well as a lack of feeling of responsibility for his actions commonly considered cruel.
The fact that he was born into an extremely wealthy family and had an above-average IQ and strength, I think only ended up accentuating those traits about him. He can't even have positive feelings towards his older brother let alone towards strangers.
As Taeui said, Ilay is extremely lonely and isolated. In circumstances that are within the norm, the person would suffer. Instead Rick doesn't even feel scratched by it. It may be a matter both innate and influenced by the environment that has surrounded him since childhood. I think since he was a little kid, no one has ever treated him normally, like a human being. That's probably why he had that kind of reaction when he got that phone call from Taeui as a kid. Taeui has always treated Ilay with humanity. Despite the other's bad deeds, even after raping him, thinking of Ilay's loneliness Tay felt pity for him.
In any case, as some comments have pointed out it is likely that Ilay is actually a psychopath. They really should label this work as psychological.

Ilay is a psychopath without a doubt. Because he doesn't feel guilty even though he killed soo many people. I like to read characters who are psychopaths. But he has more of an annoying side to him.
And even though Tay was raped, author really didn't highlight this...Here Tay is being a typical uke who only see how seme is suffering from lonely ness blah blah without pointing out what he did wrong (really annoyed me)....

I understand your pov. If I hadn't read some comments on BA*O explaining details from the novel not shown in the manhwa adaptation, I probably would have thought the same as you.
I honestly think the whole thing is very tangled. The way Tae reacted is due to his way of being, which we have actually witnessed up until now. Tae hasn't forgiven Ilay for what he did to him. Indeed, especially in the novel it seems to have been highlighted how the experience of rape was traumatic. He spent whole days in bed, unable to move because of the pain. The fact is that as much as he suffers from it, Tae is not consistent with his negative emotions. It's like he's trying to sweep it all under the rug, ignoring his pain and anger.
Tae doesn't like difficult and problematic situations. His priority is to escape from these situations or avoid them completely. In chapter 60, rather than hearing information that could put him in an uncomfortable situation, he preferred to leave despite the fact that he could barely walk. And in the novel it was pointed out that he swallowed his pain and anger he was feeling towards Ilay and the whole situation, looking on the bright side: he was still able to walk. He basically can't handle "dark"/negative situations.
He has very low self-esteem and is unable to understand his emotions, to label them. And always puts others ahead. Almost automatically, he ignores any danger to save even unknown people. And he is extremely empathetic. On these premises, it's not strange to imagine that he would have reacted in this way. He pities Ilay's lonely situation, but that doesn't mean he's forgiven him. He has had angry outbursts in the last few chapters about this incident. But this anger is not consistent. And it's just his way of being and reacting to things.
He is not a person who forgives easily. He just lets it go, he gives in. If there's something he can't do, he just doesn't do it. It's probably also for this reason that while he reacted with Xinlu, with Ilay instead he tried but only for a short time. Because he knew there was nothing he could do about it. It would have happened anyway, because Ilay is so much stronger than him.
His motto is basically "Don't think about it". He doesn't hate his comrades when they beat him, he doesn't hate his uncle after Chang-in used him at his pleasure and he doesn't even hate Ilay.
There would be other things to point out. I'll leave you the nickname on bat_o of the person who made some analysis and pointed out things showed only in the novel. I think it could be useful to better understand the situation. Unfortunately, as beautiful as this manhwa is, it seems incomplete compared to the novel.
The nickname is Seju09 ^^
This one is really underrated in my opinion. This has such a good plot not unnecessary sex. I really like the characters.
RELLAY NEED SIDE STORIES ABOUT OTHER CHARACTERS