MAJOR SPOILERS FOR BORUTO MANGA AHEAD.
Boruto chapter 66 took the manga storyline in an unexpected direction, leaving fans stunned. While the possibility of Naruto's son being killed was one that had been discussed for quite a while in the series, nobody expected his death to occur this early on in the manga.
Kawaki being the one to go through it was the least unexpected part, since it was clear that despite Naruto’s resolve to fulfill his duty as Hokage, Naruto would not be able to kill his own son, at least as long as there was some other option still available.
But what has fans most concerned right now is how the younger Uzumaki would return to life, since the first scene of both the manga and the anime had clearly shown Boruto alive, as he prepared to fight against Kawaki.
Let’s discuss some of the most prevalent theories floating around the internet right now.
Popular theories regarding Boruto’s revival in the manga
Implanting karma for a new vessel
One of the most popular theories being discussed in the fandom right now is if Boruto had given someone karma to be able to reincarnate later on. This is an idea that Kawaki suggested in chapter 56 after Momoshiki first emerged using karma and went on a rampage, destroying Sasuke’s eye.
Since both the boys' bodies were around 80% otsutsified, Kawaki theorized that it should be possible to create a vessel of his own using karma, so that he might be reincarnated after he becomes a perfect vessel and Momoshiki takes out his body permanently, erasing his existence.
The younger Uzumaki exclaimed indignantly that doing so meant sacrificing someone else, to which Kawaki mentioned Code as a viable option.
Chapter 66 mentions the “last resort”, which many fans have found to be a weirdly roundabout way of referring to simply being killed by Kawaki. That might also explain why Kawaki seemed so apathetic about killing someone he considered his brother. The only issue with this theory is that nowhere in the manga has Code been implanted with a karma.
Amado creates a cyborg body
Amado’s observations in chapter 59 of the manga also go against the theory of Boruto having implanted Code with karma. Amado mentioned that though incomplete, Code already had a karma, which made it questionable if he could even be implanted with Boruto’s karma.
The fact that Amado knew of their plans suggests that he might have offered them an alternative. The chapter basically confirmed that Amado was indeed plotting something, and chapter 66 revealed that when he was trying to coax Kawaki into agreeing to let him reconstruct karma, it was merely the illusion of a choice, with the real deed already done.
The beginning of chapter 60 makes it obvious that awakening Kawaki’s karma was far from being the full extent of Amado’s conspiracy. The container that Amado refused to tell Sumire about, which he declared would be a powerful ally for Konoha, popped up on fans’ radars again after chapter 66.
Many surmise that since Amado had the expertise to create cyborgs, and even clone people using their DNA, as seen in the case of Koji Kashin, he might be building either a cyborg body or a clone to become a vessel. If the vessel is a clone of Boruto himself, it would have the same potential to become a perfect Otsutsuki vessel after being implanted with karma.
Momoshiki saves his vessel
A less plausible theory is Momoshiki using the Otsutsuki’s regenerative powers to save his vessel. While the younger Uzumaki might not have been in on the plan, Momoshiki currently has only one vessel. Unlike Isshiki, he would not be able to simply reincarnate in someone else in case the current vessel died.
Neither can he reincarnate immediately, as Ishiki did with Jigen, due to the incomplete Otsutsification process, mainly due to it being slowed down with Amado’s medicines. So, he might try to somehow keep Boruto alive.
But the flaw in the theory is that it makes Kawaki’s initial act of killing Borushiki pointless, as the whole point has been to eliminate Momoshiki permanently.
The jougan returns
Finally, many fans have speculated that this would be the moment where the mysterious powers of the jougan become relevant again. But the biggest issue with this is that the jougan is strictly anime-canon.
Even when Boruto is shown having a white right eye in the very first panel of the manga, the eye resembled a byakugan, rather than the jougan.
There is no doubt that Boruto would return to the story, but as of now, fans are extremely confused as to how. Some fans have also speculated that Sakura might use the same jutsu on Naruto’s son that Chiyo used to revive Gaara in Naruto Shippuden, awakening Sarada’s Mangekyo Sharingan in the process. But the theory has no real basis in the manga.