Responses

I don't think the brother would try to harm him while Hangyeol could possibly get hurt. If Taehyuk hadn't pushed off Hangyeol then, they probably both would have been hit. It could be Yura imo. She doesn't treat Taehyuk as a person, more like a thing she owns. I won't put it past her to destroy something she thinks she owns just so someone else couldn't get their hands on it. Also, Hangyeol was the reason Taehyuk wanted to cut off Yura out of his life. She won't mind hurting him.
okay i had a suspicion before, but after chapter 9 the idea of older brother's involvement in that car crash sounds more and more plausible.
at first i was like 'no i get it, he has the right to be worried and nosy about his lil bro' but then shit got INTENSE, there's def high level possessiveness. if he and his friends discuss getting rid of people like it's some mundane topic at 16yo(!!!), no doubt he can arrange an accident at 31