Mirrorpool [Oath of the Gatewatch Prerelease Promos] Horror −6: You get an emblem

−6: You get an emblem with "Whenever a land enters the battlefield under your control

melted down

Sacrifice Goblin Cannon

Mines became common as cities during the days of the artificers

Each opponent who controls more lands than you can't play lands

Mirrorpool [Oath of the Gatewatch Prerelease Promos] Horror −6: You get an emblemSet: Oath of the Gatewatch Prerelease Promos Type: Land Rarity: Mythic Mirrorpool enters the battlefield tapped. {T}: Add {C}. {2}{C}, {T}, Sacrifice Mirrorpool: Copy target instant or sorcery spell you control. You may choose new targets for the copy. {4}{C}, {T}, Sacrifice Mirrorpool: Create a token that's a copy of target creature you control.