Hallowed Isle
Land-Plains Island (Rare)

(Tap: Add W or U to your mana pool.)

When Hallowed Isle enters the battlefield, sacrifice it unless you pay W.

1, Tap: Target land becomes a 2/2 white Kor creature until end of turn. It's still a land.

2U, Tap: Put a 1/1 blue Merfolk creature token with flying onto the battlefield.

Jason Staples