Honestly, HONESTLYYY, the manga/manwha artist makes a pattern of giving Hyunwoo and his ex way too much of overlap with Hyunwoo and Iltak, t this point, its not even hard to say that Hyunwoo is projecting his ex into Iltak because Iltak has been cool-buddy-buddy with him in school AND after school, added with his feminine features he's gonna be idealizing his ex onto Iltak and it would make sense on Hyunwoo's part.
On Iltak's part though, bro is just doing all of this for survival, he is getting all his shit beaten UPP, it's karma of course with the bs he's done in the past but no less tragic. His bitchy attitude is valid and irritating at the same tho, shit i would be too if mfs kept harassing me