Prime kusakabe: Complex domain
A hypothetical kusakabe where he developed a domain expansion but not the usual types. His "Complex domain" is the strongest attack a non CT having sorcerer can ever use, Kusakabe developed it purely to counter and systematically dismantle domains.
His domain is essentially a large simple domain, meaning no closed barrier, however, it's usual size is 10 meter radius, far smaller than most domains because after seeing Gojo do the basketball domain, he had the same idea to replicate it as the basis for his domain's unusual strength, that and since it's "foundation" is simple domain, it is also capable of moving with him always at the center.
Complex domain is both a sure hit domain alongside being a technique enhancing domain. It radiates a mist of CE that weakens any cursed technique that touches it (example being blue losing around 50% of it's force when entering the radius) while also acting as a sure hit that nullifies other sure hits. And since it's technically an open domain instead of a simple domain, it has no method of forced cancelation aside from deconstructing it on the spot like tengen did for kenjaku, or wounding kusakabe enough.
Earlier i said complex domain enhances Kusakabe's techniques but he has none, so naturally it would enhance simple domain! Having this domain active would mean any new shadow style move he casts inside wouldn't require the stance, nor wound up time along with an enhanced speed of travel.
And as I said, this domain was built purely to hunt other domains, this happens because the sure hit mist complex domain has would also begin applying to the barrier of domains, weakening them enough for kusakabe to just slice apart.
However, this domain is very "fragile" as in it's only maintained by the buffs from several binding vows.
Binding vow 1: the domain automatically cancels within 5 minutes.
Binding vow 2: he can only use it once a week.
Binding vow 3: his domain automatically falls the moment the other domain falls in the case of a domain clash.
Binding vow 4: in the days where he is not able to activate it, his output is lowered by 30% while on days where he can, it is lowered by just 15%
Binding vow 5: he reveals his hand.
Binding vow 6: the moment his domain falls he cannot use simple domain for 12 hours.
Binding vow 7: he must cast simple domain 4 times facing 4 different directions, and only at the intersection of where he activated the simple domains is where he can initiate complex domain.
With all of these binding vows, he is winning in a domain clash against sukuna for the 5 minutes.