*Name: Guardian Angel
Type: Instant
Play Cost: X Colorless, 1 Plains
Game Text: Prevents X damage from being dealt to any one target. Any further damage to the same target this turn can be cancelled by spending 1 mana per point of damage to be cancelled.
*Source: Front of card
*Name: Guardian Angel
Type: Instant
Play Cost: X Colorless, 1 Plains
Game Text: Prevent the next X damage that would be dealt to target creature or player this turn. Until end of turn, you may pay 1 any time you could cast an instant. If you do, prevent the next 1 damage that would be dealt to that creature or player this turn.
*Source: gatherer.wizards.com