Although stories don’t need strong themes to be good, I feel like a story such as this sends a message about self-improvement at the very least. However, making the guy from the other world take over the protagonist’s body makes a very weak statement about improvement when the protagonist just suddenly becomes OP and loses his previous personality. The way I’d go about it is to have the protagonist and Cang (the guy from the other world) share the body, like having 2 consciousnesses in a single body.
There could be an overarching storyline about Cang and the protagonist struggling to gain control over the body before reaching an understanding and coexisting, but I’ll shelve that idea as unnecessary filler for now.
When Cang enters the body, the protagonist doesn’t get any taller or change much, so he can have the drive to physically improve himself. Also, since Cang is supposed to be from fantasy medieval China land, he logically wouldn’t know much about academics, as he’s supposed to be a cultivator or something. That way, the protagonist (I legit forgot his name, I think it was Ah Mu? I’ll call him Mu from now on) can’t just get all the answers to an exam from Cang.
Basically, I want to treat the whole merging of minds as a negative thing at first, as having knowledge about medieval martial arts probably ain’t very useful in a modern country with guns and shit. Unless it’s Detroit. Plus, Cang is there whenever Mu jacks off, and has full access to his memory bank.
Over the course of the first story arc, Cang and Mu are meant to form a bond, as Cang, being a thousand years old or something, can act as the father that Mu never had (remember how in the first chapter, it was revealed he was an orphan?). If his father didn’t die before Mu could grow up, then I’ll make it so he does, while his mother dies later down the line. Initially, they could fight for control over the body, or just constantly bicker and argue, with Cang criticizing every mistake Mu makes in his day to day life.
By the end of the first arc, Mu is supposed to have gained enough confidence and courage to tell his family that he knows about their murder plot.
“But this entire story is all over the place and there are loose ends everywhere, and the author is clearly making it up along as he goes! How will you determine the first arc?” I hear you ask.
Unfortunately, everything up until now is as far as I’ve tried to make a decent story out of this while sticking to the source material as close as possible. Everything in this series becomes an even bigger dumpster fire after Cang reincarnates in Mu’s body, so the only way I can improve this story from this point on is to come up with my own fan fiction, and I honestly don’t have the energy for that.
Although, one major thing I would change is so that other people can get possessed by spirits from the other universe as well, so we can have actual villains and antagonists that can match up against Mu. Maybe his fiancé could also get wrapped up in this? I feel like the author did way too little with the fiancé.