edhseer Commander synergy, explained
Land
Add {C}.
activated {T} — adds 1 mana
Add {U} or {B}. Activate only if this land entered this turn or if you control a basic land.
activated {T} — adds 1 mana
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Hidden Lair is one).
When Hidden Lair enters:
199 other cards care about it too. These are the ones with the most connections.