edhseer Commander synergy, explained
Land
As this land enters, you may reveal a Plains or Island card from your hand. If you don't, this land enters tapped.
Add {W} or {U}.
activated {T} — adds 1 mana
Causes: nothing.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Port Town is one).
When Port Town enters:
199 other cards care about it too. These are the ones with the most connections.