Thrill-Kill Assassin is a uncommon Creature — Human Assassin card from RNA Guild Kit (GK2), collector number 54. Current market price: $0.21, 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.)