Blood Tribute is a rare Sorcery card from Commander 2017 (C17), collector number 100. Current market price: $5.08, TCGplayer market prices via Scryfall.
Kicker—Tap an untapped Vampire you control. (You may tap a Vampire you control in addition to any other costs as you cast this spell.) Target opponent loses half their life, rounded up. If this spell was kicked, you gain life equal to the life lost this way.