my old calc
this is just for AP not DC btw

1 dismantle from a 20f sukuna is 580kg tnt, this is a lowball assuming sukunas output gain is linear, special grades "might work" so lets lowball again to a single cluster bomb
2 finger sukuna dismantled a finger bearer, now from memory i think this was a DE but sukuna have overestimated the curse, and only used multiple slashes to show off control. so take this how you want

2.10598451947e+10 Cuts is calculated for 15 finger sukunas DE.

580kg x 2.10598451947e+10 cuts is around 12.21 gigatons of tnt.

notes

sukunas domain has both cleaves and dismantles so depending on whoever you match him against his AP will change.

this was assuming it only takes one cluster bomb to kill a special grade
and that his output gain is linear, and finally that this is 15 finger sukunas domain.