The thing is getting more and more tense!
Boruto: Naruto Next Generations gave clues about Momoshiki Otsutsuki’s dark plane to Kawaki in the manga’s final chapter.
Chapter 53 begins after the moment Momoshiki stabs Sasuke using Boruto’s body. Because of this, Kawaki decides to resume the fight while Sasuke and Naruto are out of place. But that’s exactly what Momoshiki wants, as he intends to use Kawaki as a sacrifice for the Ten-Tails in order to forge a new divine fruit.
In battle, Momoshiki confirms that Kawaki’s body is on “right” point and that the extraction has progressed enough for his plan to work, after all even without Karma Kawaki is still an Otsutsuki host.
So it’s clear that Momoshiki is using Boruto as a host so that he can feed Ten-Tailed Kawaki, grow a new divine tree, and bear new fruit. This means that Momoshi’s plan for Kawai is the same as Ishiki’s planned for Boruto.
Fortunately, Kawaki manages to wake Boruto up under Momoshiki’s control and end the fight for the time being. But they’re still not out of harm’s way until the villain is completely eliminated or defeated in Naruto’s son’s body.