edhseer Commander synergy, explained
Land
Add {C}.
activated {T} — adds 1 mana
Add one mana of any color. Spend this mana only to cast a Hero spell or to activate an ability of a Hero source.
activated {T} — adds 1 mana
Look at the top three cards of your library. You may reveal a Hero card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
activated {4}, {T} — searches a library
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Avengers Tower is one).
When Avengers Tower enters:
199 other cards care about it too. These are the ones with the most connections.