Even though he manipulated Nokyoung and was using him at first, after Nokyoung finally stood up for himself and left he realised just how much he truly care about him. I suspect that a similar thing would've happened in the other timeline after he found out Nokyoung killed himself
I still don't understand why hyunjae cares about nokyoung sm....look for another puppet istg.. (╬ ̄皿 ̄)凸