edhseer Commander synergy, explained
Land
Hideaway 4
This land enters tapped.
Add {R}.
activated {T} — adds 1 mana
You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Spinerock Knoll is one).
When Spinerock Knoll enters:
199 other cards care about it too. These are the ones with the most connections.