Herald's Horn [The List] Mountain Plains Swamp using their libraries as their

using their libraries as their decks

(Look at the top two cards of your library

Creatures destroyed this way can't be regenerated

and you will have release from the suffering they bring you

It becomes a 0/0 Elemental creature with vigilance and haste that's still a land

Herald's Horn [The List] Mountain Plains Swamp using their libraries as theirSet: The List Type: Artifact Rarity: Uncommon Cost: {3} As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.