Mnemonic Betrayal [Guilds of Ravnica] Rivals of Ixalan Prerelease Promos you may destroy target artifact

you may destroy target artifact or enchantment

target creature phases out until Oubliette leaves the battlefield

" —Song of the Artificer

Set: Portal Three Kingdoms Type: Creature — Boar Rarity: Uncommon Cost: {3}{B} Swampwalk (This creature can't be blocked as long as defending player controls a Swamp

you may tap or untap target permanent

Mnemonic Betrayal [Guilds of Ravnica] Rivals of Ixalan Prerelease Promos you may destroy target artifactSet: Guilds of Ravnica Type: Sorcery Rarity: Mythic Cost: {1}{U}{B} Exile all opponents' graveyards. You may cast spells from among those cards this turn, and you may spend mana as though it were mana of any type to cast those spells. At the beginning of the next end step, if any of those cards remain exiled, return them to their owners' graveyards. Exile Mnemonic Betrayal.