In the Heian Era, Oroku Saki had been a powerful Jujutsu Sorcerer. But he was like the Fallen, using his abilities for terror. Oroku Saki was known as the "Shredder" by other sorcerers. He came a few years after the Fallen, Ryomen Sukuna, had been sealed and turned into a cursed object. There were four sorcerers, one in red, one in blue, another in purple, and finally, one in orange. Those four had fought Saki and turned him into a cursed object, using the kentaku to seal Saki like others did with Sukuna's fingers. Saki was in Hell after that. And those four sorcerers were bipedal turtles named "Raphael", "Leonardo", "Donatello", and "Michelangelo". Those four tortured him until the Shredder was brought back into the Current Era.

Sukuna had a vessal, Yuji Itadori. Sukuna currently has 16 of the fingers because the final one was at the Gates of Hell. There, three of the Shredder's kentaku were locked up. The fourth and final had been stolen in another location a month prior and was used to summon the one and only Oroku Saki. AKA, the Shredder.

Now, Gojo and Sukuna were fighting at Shinjuku. Sukuna had summoned Mahoraga, Digido, and.. the Shredder.

Sukuna - "Oh, wow. Don't remember Megumi having this one.. Doesn't matter. I should definetly have control over it!"

Gojo - Mumbling "That's new,.. this wasn't apart of the Ten Shadows."

Shredder - "Finally.. THE SHREDDER IS BACK FROM HELL AND IN THIS HELL-WHOLE WORLD!"

That didn't matter because in Hell, Shredder had been cursed that by wherever he went, the turtles would be there to."