"A restorative power born from the spirit of the Champion Mipha. When your hearts run out, you'll automatically be resurrected with full health plus temporary bonus hearts."
Mipha's Grace is a Key Item found in Breath of the Wild. The item is obtained after defeating Waterblight Ganon inside of the Divine Beast Vah Ruta, as a gift from Mipha for freeing her spirit. Its sole purpose is to resurrect Link if he is to fall in battle. He will be fully healed, and also be gifted with five temporary, yellow hearts. After Mipha's Grace has taken effect, it will not be able to be used again for 24 minutes. Every six minutes the Vah Ruta icon on the HUD will fill up one quarter, and when it is completely full the item can be used again. It can be disabled within the inventory if the player desires.
When Link is in Hyrule Castle, the ability will regenerate three times faster; only taking 8 minutes to be available once more.