edhseer Commander synergy, explained
Land
This land enters tapped unless you control a Plains or an Island.
Add {R}.
activated {T} — adds 1 mana
Exile the top card of your library. Until the end of your next turn, you may play that card.
activated {3}{R}, {T} —
Causes: exile a card.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Cori Mountain Monastery is one).
When Cori Mountain Monastery enters:
199 other cards care about it too. These are the ones with the most connections.
anything is exiled — 2,497 cards in the game can cause this (Cori Mountain Monastery is one).