The way chapter 50 of the manga ended, it seemed that Boruto would become the trump card in defeating Isshiki. Why? Because there existed some unknown reason that prevented Isshiki from killing Boruto. The internet came alive with theories that suggested Momoshiki might be stronger than Isshiki, making the latter err on the side of caution.
But now that chapter 51 has dropped, we realise that these theories were not only wrong but gravely off the mark too.
The reason behind Isshiki not killing Boruto is not because of Momoshiki’s powers. It is because Boruto is a pawn in his ultimate goal, which is to cultivate the God Tree (Divine Tree) and harvest the chakra fruit.
Why can’t Isshiki Kill Boruto?
The real reason why Isshiki can’t kill Boruto is because he plans to use the latter as a sacrifice for cultivating the God Tree (divine tree) by feeding him to the Ten-Tails.
According to what Amado revealed in chapter 51, the God Tree is not a normal tree. The Ten-Tails seedling is required for growing the tree, but normal methods of planting like burying it in the soil and watering it won’t work at all. For the Divine Tree to grow, there is a special condition that has to be met. And that is to feed a living Ohtsutsuki member to the Ten-Tails.
Momoshiki is currently resurrecting inside Boruto’s body thanks to the karma seal that he granted him. This means that at some point in the future Boruto will become an Ohtsutsuki when Momoshiki manifests in him completely. Isshiki plans to feed a manifested Momoshiki to Ten-Tails in order to cultivate the God Tree.
But this plan was formulated after Isshiki met Boruto.
Ideally, Kaguya was supposed to be the one to be fed to the Ten-Tails. But she betrays Isshiki and leaves him for dead. This stalled the Ohtsutsuki’s goal and Isshiki was forced to live as a parasite. But Isshiki was still determined to go ahead with the cultivation of Divine Tree.
Before meeting Boruto, Isshiki planned to use himself as a sacrifice to cultivate the God Tree. This was because there was literally no other Ohtsutsuki he could use as a sacrifice. He gave Kawaki his karma with the intention that he would be able to revive himself after being used as a sacrifice. When he realised that even Boruto had a karma sea, he altered the plan in a way that wouldn’t require him to sacrifice himself.
Unlike Urashiki, we see that Isshiki is not afraid of Momoshiki in the least. Ishhiki only intends to keep Boruto alive, and has no qualms about inflicting injuries on him. This is visible when he breaks Boruto’s arm so that he won’t interfere anymore in the fight.
But it needs to be seen if Momoshiki will lie low without interfering in Isshiki’s plans. Do you think Momoshiki to Boruto will be what Kurama was to Naruto? The Ohtsutsuki could ultimately help the young Konoha genin, in order to prevent himself from getting sacrificed.