JUJUTSU KAISEN's plot is driven by several major twists. The first is the revelation that the antagonist Suguru Geto is actually dead, and his body is being controlled by an ancient sorcerer named Kenjaku. Kenjaku is the true mastermind behind the series' events, having orchestrated plans for centuries. His primary goal is to merge humanity with the immortal sorcerer Tengen to create one giant, chaotic cursed spirit.
The Shibuya Incident arc is the series' most critical turning point. Kenjaku succeeds in sealing Satoru Gojo, removing the biggest obstacle to his plan. This event leads to widespread chaos and the deaths of many key characters, including Kento Nanami and a presumed, brutal end for Nobara Kugisaki at the hands of Mahito. Yuji is pushed to his breaking point after Sukuna is let loose, causing mass destruction in Shibuya and killing thousands. It is also revealed that Choso, one of the Cursed Womb: Death Paintings, has a vision that Yuji is his brother, implying that Kenjaku (inhabiting the body of Yuji's mother) is Yuji's parent.
Following the Shibuya Incident, Kenjaku initiates the Culling Game, a nationwide battle royale designed to accumulate enough cursed energy for his merger plan. During this arc, Megumi Fushiguro is tragically possessed by Sukuna, who sees Megumi's Ten Shadows Technique as a more suitable vessel for his plans. Sukuna uses Megumi's body to kill his sister Tsumiki and later, to fight and ultimately kill Satoru Gojo after he is unsealed. The series finale sees Yuji and the remaining sorcerers in a final, desperate battle against a fully incarnated Sukuna. Although they manage to defeat him, the victory comes at an immense cost, with the finale leaving the future of the Jujutsu world and its few remaining sorcerers uncertain.