He redistributed the operation and burden to a different part of his brain than usual, reclaiming the lost output of the reversal technique

In the same manner, the King of Curses, Ryomen Sukuna, was supposed to regenerate all of his arms and trample over the jujutsu sorcerers
Yuji Itadori struck the boundary of souls between Toji Fushiguro and Ryomen Sukuna with seven Black Flashes. As a result, Ryomen Sukuna missed the opportunity for the revival of the reversal technique.
"Even so"


Domain Expansion: "Fukuma Shrine"


The King's Domain was returning to its master along with black sparks.