edhseer Commander synergy, explained
Snow Land
Add {C}.
activated {T} — adds 1 mana
Until end of turn, this land becomes a 2/3 Construct artifact creature. It's still a land.
activated {1}{S} — turns something into a creature
Whenever this land deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.
triggered — keeps permanents from untapping
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Frostwalk Bastion is one).
When Frostwalk Bastion enters:
199 other cards care about it too. These are the ones with the most connections.