as far as i know, pureblood werewolves have inner wolves and he has one too, and it's saying to get rid of Hwa since Hwa is part vampire and they've already made a baby inside him so Hwa is no longer necessary.
The werewolf was about to attack Hwa but the power Yibin put to protect his son react to the attack and protect Hwa from the harm. (The red thing with the eyes is Yibin power.) This power of Yibin recognize Hwa as Yibin son because they share the same blood. I am not entirely sure but it seems like Yibin power recognizes the same blood in Seolhyun stomach. So some people are speculating that Seolhyun might be pregnant.
What the fuck did happen in the last chapter ┑(￣Д ￣)┍