WARNING: The following contains major spoilers for Boruto: Naruto Next Generations #35, on sale now.
In the Naruto universe, the titular hero has faced many apocalyptic villains. The finale of the manga and the Naruto: Shippuden anime brought everything to a head with Obito, Madara and Kaguya arriving in quick succession in the Great Ninja War.
However, none of them posed quite as big a threat as the monstrous enemy who's just popped back up in the latest chapter of the Boruto manga: the Ten-Tailed Beast.
Commonly known as the Ten-Tails, it's actually the husk of the God Tree that bore chakra in Earth's early days. It's what Kaguya came to Earth to attain and, after finding its fruit, she ate it and then disseminated chakra to the rest of humanity. However, after growing restless with how their worship of her soured, she decided to take the gift of chakra back by using the God Tree as a vessel to absorb their energy and plunge mankind into an infinite sleep. Luckily, her kids, Hagoromo and Hamura, stopped her, but during the battle, the tree was actually turned into the Ten-Tails so she could wield it as a weapon.
Hagoromo would eventually extract the Ten-Tails and split it into nine beasts for human hosts to store, all after he and his brother sealed away his mother. Sadly, the tree was repurposed centuries later as the Demonic Statue of the Outer Path by Madara, and after he and Obito were used by Kaguya's minions, she brought back the Ten-Tails once more upon resurrection, combining it into her very essence. But despite having unlimited power, she was stopped by Naruto and Sasuke, even turning into a warped form of this kaiju-like monster along the way. Ultimately, we all learned a simple truth -- this isn't the creature you want coming back to life, yet Boruto #35 has it, or one of it, in action once more.
When Sasuke travels through the space-time continuum to a secret location, a temple belonging to Kaguya's clan, he finds a Ten-Tails imprisoned by chakra rods. He's in utter disbelief because he knows for someone to subjugate it like this, they must be even stronger than Kaguya. As he hides out, he sees this ninja to be Jigen, Kara's leader, and the man he was hunting all this time.
Shockingly, it turns out Jigen was Kaguya's partner and someone the clan sent to Earth with her. We don't know what happened between them, but we discover Jigen is actually drawing chakra from and feeding off this Ten-Tails (which looks eerily similar to the one previously seen in Naruto).
He's apparently powering up, even mentioning he's turning his current body into a vessel. It looks like Jigen wants the Ten-Tails to eat him when the time comes so they can both merge, similar to what happened when it consumed Madara's essence and facilitated Kaguya's rebirth. Now, we don't know if this is a Ten-Tails from another world, as the clan sent Jigen & Co. to explore a bunch of planets across the cosmos. He could have found another God Tree outside of Earth and brought it to this prison in its monster mode.
Given his scientific prowess, we also can't put it past Jigen to have successfully cloned the one on Earth from whatever remained as his lab as he's pretty good at engineering wonders of the world like Kawaki. In any case, whether or not it's the original Ten-Tails (Jigen does call it by that name), the destroyer is back. This is one of the few times we see Sasuke scared because, with Jigen at the helm, the elite shinobi seems to think the next battle with the Ten-Tails would be much more disastrous.
Boruto #36 goes on sale July 21.