To become your commander, the following things are true: If your commander would be put into a zone other than the stack or battlefield, you may put it into the command zone instead. You may cast that commander from the command zone. You pay an additional {2} for each time you’ve cast it from the command zone this game. If a commander has dealt 21 combat damage to a player while it’s a commander, that player loses the game. Damage dealt before it was your commander isn’t counted.