Domain — Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Exploding Borders deals X damage to target player or planeswalker, where X is the number of basic land types among lands you control.
Reuniting a world is not a gentle process.
(01/02/2009)
Exploding Borders has only one target: the player. If that player becomes an illegal target by the time Exploding Borders would resolve, the entire spell doesn't resolve. You won't get to search for a basic land card.
(01/02/2009)
You do what the spell says in order, so you'll put a new basic land card onto the battlefield before you determine the value of X.
(01/02/2009)
Exploding Borders will still deal damage even if you don't put a land card onto the battlefield.
(18/06/2021)
Domain abilities count the number of basic land types among lands you control, not how many lands you control or how many of any type.
(18/06/2021)
The basic land types are Plains, Island, Swamp, Mountain, and Forest. Land types other than basic land types (such as Desert) don't contribute to domain abilities.
