Thrill-Kill Assassin is a common Creature — Human Assassin card from Ravnica Remastered (RVR), collector number 94. Current market price: $0.20 (foil $0.27), TCGplayer market prices via Scryfall.
Deathtouch Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)