So it will eventually come down to Kenjaku doing the fusion dance and pulling a Gogeta or sum? Talk about smarts.
He said his goal is to merge Tengen (now a cursed spirit) with Japan's population. The emerging entity from that merger should, by his accounts, be a so far unseen mass of Cursed Energy. Basically a mega curse.
but he's not the one who had to come up with a plan from the beginning for the fight to even be a fight.
Yet, at that time, Sukuna didn't give a rats ass about Megumi and his 10S, meaning he would have to fight Gojo with his own arsenal. And we know from the Cleave and Dismantle during the first round of the fight, and the subsequent Domains, he wouldn't have won.