After reading this last chapter is obvious that Heonjae is not the best option for Myeongil, he is able to do that to his brother who has done nothing bad to him and has always tried to do the best for both of them.
I expect Heonjae to show his true colors, I think that Myeongil still hasn't seen what Heonjae is capable of. On the other hand, Jingi has shown all of it, the bad and the good parts.
I don't expect a happy ending of this story, but if Myeongil has to end up with someone I'd prefer Jingi.