Huh I would want them to have a happy ending, honestly I feel like there will be a big twist like at the end after he might find the right one he wakes up from a coma and see the guy he likes and knows who he truly is or some shit because this stuff seems like a dream you know
Why punish Doyoung though? It's not uncommon for someone to like someone without fully knowing everything about them. That is why you get to know them and that is what he was doing. It wasn't like hyung wasn't interested in getting to know him either. That part of your theory wouldn't be fair. And also you if come off like your perfect to other people how can one not believe that you aren't especially when the person that who is looking at you is someone who likes or love you?
As many people have said, I also believe that all the “Hyungs” are real and are all different aspects to his personality. But since one “Hyung” has already been eliminated, it is possible that one aspect has also been eliminated. Earlier in the story, Doyoung has only been briefly meeting with Hyung over lunches and such and therefore the probability of him having a deep understanding of who Hyung is quite small. Doyoung most likely only has his own perception of who he is and is basing his decisions off of that. While I, as many people, hope for a good ending to the story, it would be quite interesting if Doyoung is instead punished for his selfishness of hoping Hyung would be this perfect person. He would be left with no Hyung at all or instead a mere fraction of who he once was and now has to suffer the consequences.