Vanitas (ヴァニタス, Vanitasu) was the sentenial being created by Master Xehanort from darkness in Ven's heart. His name, Vanitas, means "emptiness" in Latin, but also suggests "vanity". As a result, while Ven resembles Roxas, Vanitas bears a likeness to Sora with golden yellow eyes and black hair. He originally wields a Keyblade simliar to that of Riku's Soul Eater, using a similar fighting stance and armor nearly identical to Riku's Dark Form. He monitors Ven's strength and progress in the hopes of absorbing his power prior to obtaining the χ-Blade, a powerful Keyblade that can unlock Kingdom Hearts. By the end of the game, after being defeated within Ven's subconscious, Vanitas is destroyed and the χ-Blade is shattered by Aqua in the physical realm. Ven's body is rendered dead while his damaged heart enters a young Sora.
A secret boss in the game known as the Vanitas Remnant appears after completing the final episode. It bears an appearance almost identical to Vanitas, only black and white, and with the Unversed emblem on the helmet. Its moveset is a more powerful version of the original Vanitas.