Stalking Bloodsucker

The whole design hinges on a question of what discarding a card actually costs you. A 4/4 flier for is a weak rate, and the pump ability that grows it +2/+2 looks worse still: paying and a card for a temporary boost is an exchange most decks decline outright. But the cost is calibrated for a deck that wants cards in the bin. Pitch Roar of the Wurm or another flashback spell to the activation and the discarded card stays castable from the yard, so the ability stops taxing your hand and starts feeding your back half. That assumption explains the heavy double-black commitment and the six mana value: the body was never meant for a curve-topping aggro shell hunting for a beater, but for a deck already filling its graveyard on purpose, where threshold counts and flashback recasts. Read in that light, the discard is plumbing rather than a penalty. Outside such an engine, the activated ability bleeds two mana and a card for a single attack step, and the Vampire is overpriced for what it puts on the board. It is a creature whose drawback only stops being a drawback inside the exact archetype it was built to serve, and an inert lump of stats anywhere else.