The Gazing Eye

Master Xehanort's Keyblade (マスター・ゼアノートのキーブレード) is the Keyblade used by Master Xehanort, his reincarnation "Terra-Xehanort", and his data copy, No Heart, in Kingdom Hearts Birth by Sleep.

Although Master Xehanort does not often draw his Keyblade, whenever he does fight he wields his Keyblade in this form, even after becoming Terra-Xehanort. Xehanort often uses this Keyblade to channel his own dark magic, but as a Keyblade, the weapon itself also possesses the ability to lock and unlock hearts. Master Xehanort once used this ability to extract the dark half of Ventus's heart from his body, creating Vanitas, and then again during the final battle at the Keyblade Graveyard, in order to extract his own heart and allow him to take over Terra's body and become Terra-Xehanort.

However, during his battle with Aqua, Terra's heart begins throwing off Master Xehanort's control, forcing Xehanort to use his Keyblade on their shared body to try expelling Terra, but ended up sealing away their hearts. This caused them to lose the power to summon a Keyblade. After this, Master Xehanort's Keyblade vanishes, though it is possible that Xehanort was able to regain it later, allowing him to unlock the Keyhole of Radiant Garden.

Design
Master Xehanort's Keyblade has a spiky, black guard resembling demonic wings, a horned, demonic head just above the handle, two barbed shafts, and teeth resembling a battle axe split into three almost claw-like protrusions. It resembles the Oblivion Keyblade to a degree, but with two shafts and a different head. It also contains two demonic, blue eyes; one above the handle and the other one on the head, similar to that of the Soul Eater, Way to the Dawn, and Void Gear. Its shaft and head are adorned with several twisting, silver patterns.

Master Xehanort is capable of converting his Keyblade into an orb of dark energy, which is shot into the sky to summon Kingdom Hearts. No Heart has displayed the ability to transform his keyblade into various forms including a shield-like form which creates a barrier of dark energy, a greave which he uses for kicking attacks, an arm bracer with the blade protruding past his hand for offensive capabilities, and wings for flying attacks. His Keyblade possesses a Keychain, which has a black charm with another demonic blue eye upon it.