Each opponent loses the gameExile all cards in hands and graveyardsExile all permanentsNear-infinite lifelossMass Land Denial
How it works
Cast Worldfire by paying 6, exiling all permanents, all cards in all hands and graveyards, and setting each player's life total to one.
Cast Marath from the command zone by paying and commander tax, if applicable, causing Marath to enter the battlefield with a +1/+1 counter on it for each mana spent to cast it.
Activate Marath by paying 1 and removing a +1/+1 counter from it, dealing 1 damage to any opponent.
The opponent loses the game due to having zero or less life.