Karn Liberated

The number of times a player has cast their commander from the command zone resets to zero. The amount of combat damage dealt to players by each commander is reset to 0.

No actions taken in the game that was restarted apply to the new game. For example, if you were dealt damage by Stigma Lasher in the original game, the effect that states you can't gain life doesn't carry over to the new game.

Permanents put onto the battlefield due to Karn's ability will have been under the starting controller's control continuously since the beginning of that player's first turn. Creatures among them can attack and their activated abilities with {T} in the cost can be activated.