Skirk Fire Marshal and Blessed Sanctuary on the battlefield.
You control at least five untapped Goblins.
({B} magic symbol) available.
Steps
Cast Tainted Strike by paying ({B} magic symbol) , giving Skirk Fire Marshal +1/+0 and infect until end of turn.
Activate Skirk Fire Marshal by tapping five untapped Goblins, giving each opposing creature ten -1/-1 counters and giving each opponent ten poison counters.
Each opponent loses the game as a state-based action due to having ten poison counters.