Darksteel Sentinel (TD2-016) - Duel Decks: Mirrodin Pure vs. New Phyrexia

Flash (You may cast this spell any time you could cast an instant.)
Vigilance
Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)