Skirk Fire Marshal + Blessed Sanctuary + Tainted Strike
Skirk Fire Marshal
Blessed Sanctuary
Tainted Strike
Each opponent loses the game
How it works
Cast Tainted Strike by paying , 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.