The Elder Mirror is an Elder Artefact currently in the possession of Kerapac. It was used by the Elder Gods for large-scale creation, being able to create copies of anything, including other living beings. Sakirth used it to kill V and channel his energy into Tarshak. After V's death, the Necrosyrtes placed the Elder Mirror in a location known only as the Vault.
During Sliske's Endgame, it fell into the hands of the Dactyl Dragonkin. Kerapac would channel the The Heart's anima into the mirror to overload and destroy the Stone of Jas, causing Sliske to fight against Seren, Zaros and the World Guardian.