Mark of the Vampire is a common Enchantment — Aura card from Duel Decks: Sorin vs. Tibalt (DDK), collector number 29. Current market price: $0.18, TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature gets +2/+2 and has lifelink.
All Duel Decks: Sorin vs. Tibalt cards and prices