edhseer Commander synergy, explained
Land
Hideaway 4
This land enters tapped.
Add {B}.
activated {T} — adds 1 mana
You may play the exiled card without paying its mana cost if each player has no cards in hand.
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Howltooth Hollow is one).
When Howltooth Hollow enters:
199 other cards care about it too. These are the ones with the most connections.