Based on cover the end game will be River and khaol right but the story still ongoing its looks liked river end game will be with heil??BTW they promote the untamed in chapter 50 (●'◡'●)ノ
Well this story was a novel at first but I saw a comment saying that the author dropped it because she didn't like how things were going, so I'm guessing that in the novel kahol was going to be end game but since the author saw that more than 99% of the fandom hated kahol and liked heil more she probably went for that. That's also a reason why she may have dropped the novel, because it didn't match at all with the comic.
I first thought that too, however as the author said, as the story progress, she felt like the two's relationship is like being forced, and for the two of them to end up together is probably low because their values and personalities are too different, and she had to end their relationship. she said that it is very glad that most readers doesn't hate the idea of having a new partner which is widely accepted by the readers- Heil. (me too!). So for the webtoon/manhua/comic, the end game is pretty much Heilx River.
on the other hand, just like the author said, the khaol in the novel is in a fairly forgiving? situation, so it affects the future events as well, thus I am inclined to think that river and khaol might end up together in the novel.
From chapter 2 till chapter 20++ really makes me anxious kimin really crazy.