The MC is truly in love and says he would never betray her or be with anyone else, ever. But Lo and behold, it turns into a harem. Love interest nr 2 keeps nagging MC, telling how much she loves him, and he just caves in, totally going against his “pure” and honest character. MC says that he might never love Nr2, but she can at least “be with him and Nr1” What the f*ck!? It seriously doesn’t make any sense at all, I guess the author wanted a threesome, and this was as close as he could get.

when the MC decides to free the archenemies of the human race over love (especially one where its development is lacking)

would betray his friends, country, and family for a girl. These demons, though I'm not prejudiced towards them, came to annihilate the human race. If their plot was successful, then everyone including his family, teachers, friends, etc. Would all be dead.

The MC suddenly became and idiot. He did a childish trick on the girl for a s*upid reason. He confessed his love for her so that he can dump her after she develops feelings for him. However after some time he magic~~ly fell in love with her and she... the same. Afterwards the story goes even more down hill. The plotline becomes worse and the MC becomes s*upider. The characters slowly lose their personalities and now Zhan Gong - the MC- suddenly has a harem even though he claimed he'll only love the Female lead. The current events all feel forced

So for the ending..... it is a catastrophe both in the literal sense and the literary sense. So the big evil is a monster that needs a living person as a vessel and takes advantage of the gaps in peoples heart to posses them and the one who got possessed is one of the MCs girlfriends because apperently he never showed any signs of really liking her even though they nearly had s*x with each other once and kissed each other and resolved the problem with him having more than one parter one chapter before the possesion happend so plothole mumber one. Then in the fight he kills her body so he can take her over more easily. Like you spent 3 f*cking days trying to completely posses her and in the end you didn't even need her alive so you could just have done this from the very beginning or I don't know take one of these dead swordmasters (Yes most of them didn't even get names) which are far stronger than her and could have killed everything fast enough that he would succeed with his world conquest. No why should he do such logical things. Plothole 2.

Meanwhile "all" the strong characters are supporting the MC in the fight. And by all I mean a select few while the rest is at first keept at bay by other monsters but after some time all these monsters are dead and these guys still just watch from the sidelines.

Meanwhile MC gets possessed after he sees girlfriend 1 dying. Girlfriend 2 tries to help him while the rest of his friends just escape on his dragon, that should only listen to his orders, instead of trying to help girlfriend 2, who is their only hope in bringing MC back to his senses.

Girlfriend 2 uses some secret technique to get Monster King out of MCs body but dies because of said technique and just in this moment the devine being that ordered them to kill the Monster King shows up and finishes him of even though it has been established that it can't kill the Monster King until the part of it they were fighting till now is dead and you'd expect the devine being to revive the dead people as a reward for the MC. Nope the MC gets a lifespan of 60 years and nothing else, because apperently he is at fault for killing half the world population while the Monster King possessed him, even though he only blew up one fortress during that timeframe.

MC says he is going to search for magic that can revive people and the story ends there.

We do get a glimpse of what happend to MC in Douluo Dalu 2 where he becomes Calamity Necromancer Electrolux and as his name suggests wasn't very successful in reviving the dead but that was it and it is just so unsatisfactory.

MC goes to see his beloved muzzy in the demon kingdom. His face gets ruined by dark attributes in the process and because his 'handsome' face is now hideous, he pretty much throws her aside with the excuse 'I'm to ugly for u now'. Like srsly, just wear a fking mask! The author doesn't seem smart enuf to think of such idea, so he just has the MC walk around with such a face and have him lose confident with himself, thus leading to his constant 'I'm not good for u' statements towards the female lead who he went to see. It's REALLY f**ing annoying having to read him avoid her cuz his face. He didn't even have a proper talk with her!

Whenever I read anything about his face, I'm like 'here we go again'. I wish the author had planted the idea of a mask and made him more like a 'mysterious' figure later. But instead he had to make him into low confident guy who uses his face to avoid his 'true love'. Srsly, Just deal with it bro. This is how ugly ppl feel. Move on!