See also: Mythril Equipment.

In Final Fantasy III the Mythril Ring is used to banish the Djinn and remove the curse that was placed on the people of Sasune and Kazus. Originally give to King Sasune by Takka, Refia's adopted father, it was passed on to Princess Sara who took it with her into the Sealed Cave, where you meet Sara in the game.

When the party meets Sara, she ask to join them and defeat Djiin, but when they fight him, Djiin had the power of the darkness, rendering the Mythril Ring useless. It was only after the party fought him and won that Princess Sara could use the Ring to defeat him, washing it on the sacred spring of Sasune Castle.