Gift of Immortality is a rare Enchantment — Aura card from Theros (THS), collector number 14. Current market price: $0.72 (foil $17.63), TCGplayer market prices via Scryfall.
Enchant creature When enchanted creature dies, return that card to the battlefield under its owner's control. Return this card to the battlefield attached to that creature at the beginning of the next end step.