Putting a land onto the battlefield this way doesn't count as playing a land and can be done even if you've played a land this turn or if it isn't your turn
Creature - Human Soldier Color tag templates(None) Catapult Master Tap five untapped Soldiers you control: Exile target creature
If you do, when this creature enters, create a 1/1 token copy of it.) When this creature enters, tap up to one target creature and put a stun counter on it
Sac lands, cycling lands and an abundance of other effects, many of which are black and green, easily fill the yard full of lands to allow prolonged mana influx from the Shaman
Gandalf the White We know doubling enter abilities is very popular
While this ability requires Roon to be tapped, it can flexibly be used at instant speed to either gain the benefits of an enter the battlefield trigger or to temporarily remove an opponent's key creature