So... Am I the only one who understands Yuta's behaviour🙏😭
What he did to Seunghyun is a trauma response. We saw the flashbacks and I 100% understand him. He was left by Seunghyun in a few situations and now despises him.
I am not excusing his behaviour, I just want yall to understand that this is how cycles of abuse start. One person gets abused, then they lash out because they're scared- or they were raised that way. 
Yuta is scared of many things(in my opinion), like being left alone again or even being seen as soft- which can all lead to the fear of being abandoned again.