edhseer Commander synergy, explained
Land
Add {B} for each Swamp you control.
activated {2}, {T} — adds mana
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Cabal Coffers is one).
When Cabal Coffers enters:
199 other cards care about it too. These are the ones with the most connections.