Boruto: Naruto Next Generations somehow got even darker in its latest chapter, as we finally get the answer to the mystery of what new villain Isshiki Otsutsuki plans to do with Boruto. Up until now we've had small foreshadows about the connection between Boruto and Kara: the evil organization has made a point of not killing Bourto in battle, but to what end was unclear. Complicating the situation is the fact that Boruto has been marked as a vessel for Momoshiki Otsutsuki; it's been very unclear what kind of relationship (or not) existed between Isshiki and Momoshiki - but now we have that answer!
Warning - Boruto Manga Chapter 51 SPOILERS Follow!
Boruto Chapter 51 sees Naruto, Boruto, and Sasuke facing Isshiki in battle, over in the alternate dimension that Boruto warped them to. Boruto stopped Isshiki from killing Naruto and Sasuke by leveraging his own life against the villain - and it worked. Isshiki backs down - at least, for a moment.
The manga chapter lays it out in alternating scenes of what's taking place on the battlefield with Isshiki, and the hiding room in Konohagakure, where Kara's traitor Amado is discussing the rituals of the Otsutsuki with Shikamaru and Isshiki's former vessel Kawaki. The bottom line is a horrific reveal: Boruto is meant to be food for the Ten Tails that Isshiki will use to grow a Divine Tree and consume Earth's chakra!
More specifically: it's the Momoshiki essence inside of Boruto that Ten-Tails needs to a consume, in order to transform into the Divine Tree. As it turns out, the reason that Otsutsuki are paired together for their invasion of other planets: one to sacrifice him/herself to the Ten Tails, the other to grow the Divine Tree and harvest its Chakra Fruit. The Otsutsuki who died in the sacrifice would then be resurrected through the Karma seal and its appointed vessel.
When Isshiki learned that Boruto was the vessel for Momoshiki it presented a unique opportunity. Amado reveals that like any harvested crop, a Divine Tree and the strenth of its Chakra Fruit are relative to the power of the Otsutsuki a Ten Tails consumes. In this Instance, Momoshiki is a much younger and more vital Otsutsuki than Isshiki, and would therefore conceivably provide a much better crop of Chakra Fruit for Isshiki to consume. Therefore, Boruto must be kept alive until the Ten Tails can consume him.
...Unfortunately, Boruto overestimates his own importance. As Isshiki demonstrates with shocking brutality, the need to keep Boruto alive is not the same as keeping him unharmed.
You and read Boruto's latest manga HERE. The anime has resumed streaming on Funimation and Hulu.