Voldaren Thrillseeker is a rare Creature — Vampire Warrior card from March of the Machine Promos (PMOM), collector number 171p. Current market price: $0.22 (foil $0.50), TCGplayer market prices via Scryfall.
Backup 2 (When this creature enters, put two +1/+1 counters on target creature. If that's another creature, it gains the following ability until end of turn.) {1}, Sacrifice this creature: It deals damage equal to its power to any target.