Aurora Eidolon is a common Creature — Spirit card from Dissension (DIS), collector number 1. Current market price: $0.24 (foil $1.18), TCGplayer market prices via Scryfall.
{W}, Sacrifice this creature: Prevent the next 3 damage that would be dealt to any target this turn. Whenever you cast a multicolored spell, you may return this card from your graveyard to your hand.