The MC is technically MENTALLY DISABLE him having a split personality is a big misunderstanding. What we call as a dark side was just suppress negative emotion from his childhood experience. In a way to survive all those traumatic bullying he suppress those negative feeling that is why must reader think that MC is dense or a hypocrite who shout justice and peace loving but in reality that is just a side effect from all the bullying he experience.

MC was bullied?

MC first love is a Sl*T and for some odd reason hated the MC she was also the major reason for his school bullying. (Imagine your crush who knows you love her beat you up and have s*x in front of you) I can some how understand the girl's reasoning on why she want to bully the MC as the MC at that time is simply a moving punching bag as a result of sealing all the negative effect that comes from the bullying his emotion are almost null and void and what's left is that happy go lucky attitude and who always aim for world peace.

Like they said be-careful of a cheerful and happy person never you know what kind of darkness is hidden in its heart.

As for MC power up will we can just let PLOT ARMOR take the credit I mean he is called MC for a reason.

I certainly dislike some female counter part especially that rich girl with her air head friend their combination seems unnecessary for the story I seriously hope that the author drop them and forget them since they are what we can call a SUPER EXTRA side characters, Their relationship to MC is vague lets not talk about romance as the MC never once admit that he LOVE them as MC only love 1 person at the moment.

The classmate girl who sit next to MC who chase MC all the way to college has some promise but she certainly needed some serious appearance since she is barely mention in the story (I hope instead of the two girls I mentioned the author can focus with this girl)

The Japanese girl that the MC r*pe in another point of view I can say that their was no R*pe, Why? First the girl was willing, second after the deed was done the girl accepted the MC although we cannot deny that their is racial discrimination but who cares about that this is just a story only a sever hypocrite would shout out racism from a fictional novel. So far this Japanese girl also has a potential to be MC's partner so I hope we stop saying that she was R*pe by the MC.

And last is the FOX girl (Their are other girls in the story but since their relationship with MC is in sister brother level I will not mention them as they rarely appear in the story) this girl is the main love interest of MC honestly I was disappointed as so far she was just like a nanny for the MC. Despite MC saying he loves her their was no romantic scene for them (have they ever kiss? I forgot)

MC was like booom "I am so OP" then got his ass kick and is save by plot armor

seriously after making one Young Master r*pe another Young Master neither is mentioned again though one young master's father still has a grudge against him brought up that is it.

Based on what some others have said and what I know he should just kill Ma Yixuan, she hates him for no reason and instead of saying something to him to get him to give up she has purposefully gotten his hopes up before knowing he liked her and at other times tried to have her boyfriend and his goons beat him badly because she is disgusted by him. At the point I'm at I have to say why hasn't she knowingly attacked the MC yet, she thinks he is strong but doesn't know he is a cultivator so she should try to attack him seeing as she is already on the same realm as him (technically until just recently she was higher). Though I have to say part of their relationships reminds me of the first part of Pure Love x Insult Complex where the older sister is Yukino (to an extreme), the younger sister is mana and the main character is Yoshinobu. By that I mean he is disillusioned by his first love and while he holds a fondness for her has gotten over her and the younger sister is actually salvageable and they were actually both mistreated by the older sister.

He also essentially creates his own private army which is pretty boss

dark side or evil side most likely a split personality, depending on how the story goes he can become the strongest God in the world or the worst and most evil demon lord.