WARNING: The following article contains major spoilers for Boruto: Naruto Next Generations #39 by Masashi Kishimoto, Mikio Ikemoto and Ukyo Kodachi, on sale now.
With Jigen showing his hand as the vessel for Isshiki Ōtsutsuki, the Boruto manga has changed drastically since we now know just how powerful the tyrant truly is. To set an example, Naruto was taken by the villain to a secret dimension and sealed away there, leaving a bloodied and bruised Sasuke retreating to Konoha to lick his wounds in a team-up gone awry.
Still, even with Sasuke barely alive, it's the Hokage that the village usually relies on. No matter which ninjas are still kicking, whether it be Kakashi, Guy, Sasuke, Konohamaru or Naruto's son, all hopes feels lost without Naruto around. Thankfully, Boruto #39 has revealed the key to finding the legendary shinobi and it's surprisingly tied to Boruto and Kawaki's Karma marks.
These cursed seals were initially thought to be evil, since they empowered both young ninjas to levels Naruto and Sasuke had to work for years to get to. Boruto got his mark after battling the Kinshiki and Momoshiki while Kawaki got his when Jigen engineered his body to be a replacement for Isshiki at the Kara science headquarters. While these ninjas'extra chakra and upgraded abilities made them too dangerous for their age, the marks hurt them once they were activated, wrecking them to the point that it seemed as if the seals were meant to corrupt the kids, turning them into weapons of mass destruction.
We saw such seals transform at-risk youth like Sasuke into full-blown terrorists, especially during the Orochimaru and Kabuto eras, and clearly, these new seals were the markers for Isshiki to be transferred into. But now, it looks like the boys can harness these cursed marks for good to track Naruto down.
Following Jigen's assault on Naruto's home, Kawaki lost his prosthetic arm, only to discover it still possesses Naruto's chakra when the forensic team rolls through. Naruto embedded it with his energy to help Kawaki heal mentally and physically from Jigen's experiments weeks before. Since the chakra signature inside it goes live again, Kawaki quickly pieces together that Naruto's still alive, and what he does next shows exactly why Jigen thinks of him as the perfect vessel.
Jigen entered Naruto's home through a portal generated by Kawaki's mark, which suggests Jigen always had a stamp on the youngster's chakra. Kawaki decides to apply the same logic using the prosthetic, forcing his Karma to activate and trace the Hokage's chakra footprint. However, Boruto's Karma activates as well, right after Kawaki urges him to focus on the location he's pinpointed, since he's expending a lot of energy opening the rift by himself.
The marks unite -- similar to Naruto and Sasuke when they fought Kaguya using marks from the Sage of the Six Paths -- and a portal fully opens, which allows them to find the hole in space and time where Naruto is being kept prisoner. This evolves the brotherhood between Kawaki and Boruto even more, flipping the script on a pair of marks we thought would only be trouble. Boruto even absorbs Shikamaru's Shadow Paralysis jutsu using his Karma to reiterate that no one's going to stop their daring rescue mission. As it turns out, as much as Karma is the harbinger of destruction, it's ironically the key to saving Naruto and the ninja villages once again.