edhseer Commander synergy, explained
Land
Add one mana of any color. An opponent gains control of this land at the beginning of the next end step.
activated {T} — adds 1 mana
activated {T} —
Causes: take control of a land.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Rainbow Vale is one).
When Rainbow Vale enters:
199 other cards care about it too. These are the ones with the most connections.