Spoiler warning: Plot or ending details follow.

"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."
— In-game description
"It was my pleasure."

Mipha's Grace is a key item from The Legend of Zelda: Breath of the Wild. Link obtains this power from Mipha after defeating Waterblight Ganon in the Divine Beast Vah Ruta. It can be deactivated and activated at will by equipping or deselecting it at the Key Items menu. It is a blue orb that has a symbol of Vah Ruta in the center.

Mipha's Grace revives Link upon death, much like a Fairy. However, Mipha's Grace restores all of his health whereas a Fairy only restores five Heart Containers, and it also grants Link five bonus yellow hearts. It has a 24-minute cool-down period after Link has been revived from death. Mipha's Grace activates before any Fairies Link may be carrying.

Mipha's Grace become upgraded to Mipha's Grace + after completing the quest EX Champion Mipha's Song in The Champions' Ballad DLC. The cool-down is reduced to 8 minutes.

Spoiler warning: Spoilers end here.