Flashback to earlier that day. Shikamaru (now the Eighth Hokage) explains to Sarada and Mitsuki that before Naruto and Hinata were sealed away, Naruto left a final contingency: a key to a seal that predates Kaguya, hidden in Uzushio. "Boruto and Kawaki both have Otsutsuki powers," Shikamaru says. "But the Ten Tails' original husk—the one Jura came from—has a weakness. A 'Seal of Origin' that can reset its will to zero. Without that, Boruto's plan to save your father is just suicide."
Back in Uzushio, Sarada and Mitsuki find the seal chamber—but the central altar is shattered. Inside is a single broken horn, pulsing with dark chakra. Sarada touches it and gets a vision: Jura, years ago (in Otsutsuki time), tearing through the Uzumaki shrine and absorbing the "memory of sealing." The horn is all that remains. Boruto Two Blue Vortex Manga Ch 81
Suddenly, a Claw Mark rips open behind them. Jura steps out—not in his full giant form, but as a smaller, faster, humanoid predator. He doesn't attack Boruto. Instead, he smiles. "You think the seal in Uzushio will save your father. But Uzushio has no seal left, Boruto Uzumaki. I already consumed it." Flashback to earlier that day
Two Blue Vortex – Chapter 81: "The Last Unbroken Seal" "But the Ten Tails' original husk—the one Jura
A single panel. Deep underground, in a forgotten Otsutsuki dimension, a young girl with Naruto's whisker marks and Kaguya's Byakugan opens her eyes. She is trapped in a crystal, a shinobi headband at her feet—the symbol of the Rain village crossed out. Beside her, a journal with a single entry: