Landfall - Whenever a land enters the battlefield under your control, target player other than you creates a 1/1 green Spirit creature token with "Whenever this creature dies, put a +1/+1 counter on target creature."

Next Step - At the start of your upkeep, if your team controls 15 or more lands, remove Mathida, Soul Warden from the game. Mathida, Soul Wanderer is your new commander.