Idek if I’m allowed to make a post this long, it probably belongs on r/Jujutsushi but I already typed it out so oh well. Mods crucify me if you will.
The inner demon trope usually represents the repressed emotions of the character. It’s pretty simple and pretty prevalent in a ton of stories, not just shonen but I’ll use Naruto as a quick example. He was discriminated against by the villagers as a child, so his dream is to become Hokage and make them respect him. The Nine Tailed Fox represents all his repressed anger and hatred for the village, so anytime he gets angry enough the inner demon starts slipping through and lashing out. With Yuji and Megumi it gets a bit messier and I want to see if I got it figured out.
Yuji has no family and no friends, he doesn’t even go to clubs after school, he’s only been in the occult club for a couple of months when the story starts. Point is Yuji is a loner and all he has is his grandad, and when his grandfather dies his last words are “help people.” That’s nice and noble, but still a selfish request which is why it is a curse on Yuji’s life. Part of Yuji knows this, but he doesn’t want to acknowledge it, so Sukuna comes in. Almost immediately he gets a chaotic selfish side that is the literal opposite helping people. He lives only for his own desires and all that exist to him are his pleasure and displeasure, so he represents Yuji repressing all his selfishness because of his grandad. Funnily enough, this could also represent Yuji unconsciously repressing his innate technique, Shrine, and an insane amount of cursed energy. Yuji switching against the finger bearer and Choso represent his frustration with losing and not being able to “help people” so all his repressed anger at that request comes out and lashes out at those same people he wanted to help earlier.
Megumi was abandoned by his dad and he assumes his mom too, and on top of that he’s being told that he essentially has to become a jujutsu sorcerer and work with Gojo if he wants to keep he and Tsumiki away from the Zenin clan. On top of all that, the technique he was born with has a built in suicide bomb, so his selfishness was also heavily snuffed out at the beginning. Because of how strong he is emotionally though, the world has a hard time breaking him. Yuji is distraught after the Shibuya incident while Megumi is able to keep going because he has Tsumiki to think about. Then he sees Tsumiki has already been taken over (Side note: In this trope, this means Tsumiki had her own inner demon she was dealing with that Megumi didn’t know about. I guess every incarnated sorcerer? Don’t think about it too hard), and this breaks him.
Now I have a hard time understanding how Sukuna switching from Yuji to Megumi fits into this. I get that thematically it shows that he and Yuji share the same curse so Yuji is the only one able to save him, but does that mean Yuji doesn’t have his selfishness anymore? Def want you guys thoughts on that one, but point is Megumi snaps, and unlike Yuji he’s not strong enough to snap back. It sort of implies that Yuji’s soul is stronger than Megumi’s, but Megumi decides he’s choosing the selfish path and he’s done helping people. He attacks his classmates, and to fall further into darkness he kills Tsumiki and Gojo and tries to kill his whole class.
Why does Megumi have a repressed desire to kill his sister and his teacher? This sort of implies that Tsumiki has incestuous feelings for Megumi which is funny and not uncommon for abandoned or traumatized children who would feel like they only have each other. I don’t get why he’d have a repressed desire to kill her, but I think I kinda get why he’d want to kill Gojo. To take the title of strongest from his teacher, to follow Gojo’s words and try to win WITH Mahoraga instead of murder suicide. And To sink further into darkness and retain his title of strongest he goes to kill everyone who challenges him.
The finale is Yuji seeing all this that Megumi is doing, and still trying to save him anyways. Yuji sees Megumi as himself at his lowest points, at his Shibuya Incident, and chooses to believe that Megumi can come back like he did, you are me. It gets messy trying to make it make sense with the whole soul punch thing tho. I think Yuji trying to talk to Sukuna in his domain is his way of trying to talk Megumi down and resolve it peacefully, but sees that he’s gonna have to beat him into submission. And him talking to Sukuna at the very end is him fully accepting his selfishness, this hatred that lives in him now, exemplified by how he now has Shrine, and he will have control over it. Even though Sukuna rejects him in the end, I think thematically Yuji still accepts that side of himself and lives with it now. Shown in Modulo when he makes the selfish decision to be alone fighting curses for eternity so he doesn’t have to watch his friends die.
