Sukuna is actually Itadori’s uncle. It’s not a typical family situation. Sukuna had a twin in the womb, but Sukuna absorbed his twin sibling’s energy. It’s pretty messed up, but it explains a lot about why Sukuna is so insanely powerful. If he hadn’t done that, he might’ve been born weak and never been that powerful.
In the Jujutsu world, twins share the same soul. We saw this play out with Maki getting a massive power boost after Mai’s death; applying that same logic, Jin Itadori’s soul is essentially a fragment of Sukuna’s soul. That’s the spiritual link between Yuji and Sukuna, coming through his dad.
But Kenjaku, that brain-switching curse we’ve been trying to figure out, is involved too. He possessed Yuji’s mom, Kaori Itadori, and used her body to conceive Yuji with Jin. It’s like Yuji was engineered from the start to be the perfect vessel for Sukuna. The more I think about it, the more it seems like Yuji’s entire existence was planned out as part of some grand, messed-up scheme.
Yuji was always strong, even before he knew anything about Cursed Energy; here’s an explanation for that, too. It turns out that Kenjaku had sealed a Sukuna finger inside Yuji from birth. It’s crazy, but it explains so much. In the very first chapter when Megumi sensed something off about Yuji, even though he didn’t have any cursed objects on him, That’s because Yuji already had Sukuna’s Cursed Energy.
This whole thing is why Yuji could survive eating Sukuna’s finger when it would’ve killed anyone else. He already had a built-in resistance to Sukuna’s Cursed Energy. It’s like he was tailor-made to be Sukuna’s vessel.
The more I think about it, the more connections I see. It’s got me questioning everything about Itadori’s role in the story now. Jujutsu Kaisen just keeps getting deeper and more complex with each revelation.