Before the start of the game, add ten room counters to yourself.
When an opposing troop enters play, add a room counter to that troop. Remove a room counter from this.
At the start of your turn, remove a room counter from this. Then, if there are zero room counters on this, destroy each troop with zero room counters. Remove a room counter from a random troop.
When an opposing troop dies, if opposing champions control no troops, destroy each opposing champion.