Sukuna had a binding vow with Yuji. The King of Curses agreed to revive the boy after his apparent death under two conditions: ① Yuji would allow Sukuna to take over his body for one minute when the latter chants "Enchain" (契けい闊かつ Keikatsu?) and ② he would forget about the...
Dismantle/Cleave is a part of Shrine which IS Sukuna's technique, he has mastered it to perfection given he has a perfect domain and is infinitely more knowledgeable than Yuji, so it should apply on Sukuna as well, as it's his technique afterall which he had for years while Yuj...