The Keyblade Heart, the second weapon of choice of Riku.
The Keyblade of Heart is a keyblade, created by Ansem from the "pure hearts" of the Princesses of Heart, temporary serving as one of Riku's keyblades, while being under the influence of Ansem. It's immense power is used in combat against enemies like Sora and his friends. It also appears in the second Disney Villains War, as the second weapon of choice of Riku, before his defeat by Xemnas.