The history of Jujutsu Kaisen is very somber, much darker than other fighting shonen, especially considering the ones from the same manga magazine, Weekly Shonen Jump. This mix of Naruto and Hunter x Hunter has developed in a unique way thanks to the dynamic between the different protagonists and antagonists.
Yuji Itadori is the actual protagonist of Jujutsu Kaisen and he’s a very brave and selfless character who fights to protect his friends and the innocent, which, in the words of his late grandfather, he wanted to make clear from the first chapter. He has a sunny and friendly personality and is very respectful of other people. However, beneath the surface lurks a dark and foreboding side due to the presence of the sukuna within him.
And that’s right Ryomen Sukuna is said to have betrayed him, if you can say so, in the final chapters of Jujutsu Kaisen. The transference of the curse into Megumi Fushiguro’s body caused Yuji to panic, who believed he had finally found his purpose in life. In fact, until now the boy had thought of becoming the container of all of Sukuna’s power, suppressing it and carrying it within him until the moment he would be executed, sealing the horrid fallen being forever. This role as a cog in something bigger made Yuji a very special character in the Shonen landscape, and it was a goal that made him happy despite the death that surrounded him.
And yet that goal was snatched from his grasp. With Sukuna possessing Megumi’s body, Yuji finds himself in a crisis more than ever: he’s lost his two groupmates, he’s lost a master, he’s lost his purpose in life, and he can’t lift a finger against his toughest enemy, who is him instead exploited to the last. And now Yuji is also losing some of his power and is still inferior to Sukuna, as evidenced by the powerful punch that knocks him off in Jujutsu Kaisen 213.
Will Yuji Itadori be happy at the end of Jujutsu Kaisen?? Apparently not, because if the situation stayed like this, he would be forced to permanently kill Megumi and live a life where he couldn’t help one of his closest friends. Given that, it seems that Gege Akutami wants to go down this path Jujutsu Kaisen is a very dark manga exactly as the author intended.