MAGIC: THE GATHERING
, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card and put it onto the battlefield. Then shuffle your library.
The Onslaught “fetchlands” are a staple of every constructed format in which they are legal. These lands re-entered Standard with a reprint in Khans of Tarkir, and they are currently banned in Pioneer.