edhseer Commander synergy, explained
Land
This land enters tapped.
Add one mana of any color in your commander's color identity.
activated {T} — adds 1 mana
Target creature you control with a counter on it gains lifelink until end of turn.
activated {2}, {T} — grants a keyword
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Hidden Hideout is one).
When Hidden Hideout enters:
199 other cards care about it too. These are the ones with the most connections.