Blue Vortex Manga Ch 81 | Boruto Two

Koji's eyes widen. "The key Saisei spoke of... it's not a weapon. It's a person. Someone who shouldn't exist in this timeline. Someone who is neither human nor Otsutsuki. Boruto... you have a sibling."

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." Boruto Two Blue Vortex Manga Ch 81

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: Koji's eyes widen

Two Blue Vortex – Chapter 81: "The Last Unbroken Seal" It's a person