edhseer Commander synergy, explained
Land
This land enters tapped.
When this land enters, return a land you control to its owner's hand.
triggered — bounce
Add {U}{R}.
activated {T} — adds 2 mana
Causes: a land leaves the battlefield.
Cares about: nothing.
a land enters the battlefield — 1,560 cards in the game can cause this (Izzet Boilerworks is one).
When Izzet Boilerworks enters:
199 other cards care about it too. These are the ones with the most connections.