It puts a +1/+1 counter on the Walker, making it sort of an Ancient Tomb when you have an odd amount of mana, but then it can also put a counter on a Thopter later
Lands are like the Pokmon TCGs energy cards - except instead of attaching them to a unit, you place them on the field and tap them each turn, like a resource pool
the ability to answer a threat without lowering your land count is just too good to pass up
You can directly tutor Field of the Dead out from your deck with Crop Rotation by trading any one land for it by sacrificing it, or Urza's Cave, which can sacrifice itself for three mana to put any land from your library onto the battlefield
But if you fill me in on any missing cards, I promise I wont flash in my Notion Thief when you cast your Recurring Insight
Weve yet to see the mechanic on any newly minted cards, confirming it isnt an evergreen mechanic