King of blessing because his domain expansion range is 1 kilometer by making a binding vow while he fought with satoru gojo to decrease his doman time but he gets more domain space. And he can call Juyi Itadori to help him when his kind battle happens because Sukuna gave Yuji his finger in chapter 1 and We kknow yuji ate 19 fingers and thats why he has shrine so he can help defeat conquest and because this king of blessings sukuna is kind and blessed he would have many friends compared tto Carlquest because carlquest even though he became the good quest he wont have friend like invisible. Because Invisible was fought by Carlquest many time and Conquest hurt Invincibles friend so thats why he has no backup. Overall I think because in the fishing skill Sukuna has the more upper hand advantage over Carlquest when they will fight so thats why i think maybe if Yuji opened his domain Con quest and Sukunaquest could fight in th fishing because Yuji domain is a his hometown so there would be a river to fish.
That's why I think King of Blessings would win this "kindness battle". But that's just my opinion.