WARNING: The following contains major spoilers for Boruto: Naruto Next Generations #43 by Masashi Kishimoto, Mikio Ikemoto and Ukyo Kodachi, available in English from Viz Media.

Boruto continues to be pushed to the limits in his manga as he tries to free his father, Naruto, from the clutches of Kara. The terrorists, led by Jigen, have trapped the Hokage of Konoha in a secret dimension, resulting in Boruto's Team 7 heading there to rescue the leader.

But with the assassin Boro proving too much to handle, Boruto has no choice but to pull out all the stops as he realizes it's a fight to the death. Desperate times call for desperate measures, so he relies on the full strength on his sinister Karma mark. In the process, as Boruto: Naruto Next Generation #43 reveals, he upgrades his father's biggest weapon in the deadliest way. but if he's to continue drawing strength from this particular chakra reservoir, he may end up losing his soul -- and his humanity.

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The weapon is the Rasengan, a powerful energy blast connected to wind, which was handed down from Jiraiya to Naruto's father, Minato; his student, Kakashi, then taught it to Naruto. It became Naruto's signature move, and then Konohamaru perfected it. In the fight against Boro, Boruto and Kawaki combined their Karma marks to create what we thought was the most powerful version of the Rasengan, at least until now. However, this comes at a price, as it evolves when Boruto is possessed by what seems to be Momoshiki.

When Boruto's body becomes warped and he sprouts a horn, it's obvious there's an Ōtsutsuki clan member inside of him. Previous issues indicated when he defeated Momoshiki, the alien left an imprint on Boruto -- that is, the Karma mark -- in order to one day corrupt the boy and use him as a vessel. And just when Boro is about to kill Boruto, the mark manifests in full. Boro is turned into a giant monster, but he can't squash the boy because the alien has ramped up his powers exponentially, especially after pulling some chakra from Naruto. We hear it trying to pick out a move to survive, and it selects the Rasengan, turning it into a nuclear attack against Boro. The warped Boruto unleashes this weapon of mass destruction, literally the largest Rasengan we've ever witnessed, and it drops on the villain like a storm, disintegrating him.

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It may well be the singular most powerful shinobi attack in the series, leaving no trace of the target behind. When Boruto snaps back mentally, he can't even recall what happened. It just goes to show how possessed he was. This actually feels like when Naruto got upgrades and power boosts from the Nine Tails, Kurama, inside him. But unlike his dad who bonded with the demon fox and could tap into those chakra reserves when need be, we don't know if Boruto will be offered this same courtesy.

Naruto and Kurama had a partnership -- a mutual understanding -- but Momoshiki seems to be more of a symbiote. If Boruto keeps allowing himself to be used as a host, Momoshiki might grow stronger and, bit by bit, move steps closer to fully owning the boy's body; he has to tread carefully. It's why his friends are concerned, because they know Boruto is in big trouble with the entity inside him.

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