Melmetal (SM181) (Staff Prerelease Promo) [Sun & Moon: Black Star Promos]Set: Sun & Moon: Black Star Promos Type: Metal Rarity: Promo Retreat cost: Colorless,Colorless,Colorless,Colorless

−7: Exile the top seven cards of your library

Two-Headed Dragon can block an additional creature each combat

put all cards exiled with Knowledge Vault into their owner's graveyard

Set: Sun & Moon: Guardians Rising Type: Psychic Rarity: Secret Rare Retreat cost: Colorless

Set: Secret Lair Drop Series Type: Sorcery Rarity: Rare Cost: {2}{B}{B} Destroy all creatures

Not content with mere answers

Set: Expedition: Base Set Type: Darkness Rarity: Holo Rare Retreat cost: Colorless

Set: Limited Edition Alpha Type: Enchantment — Aura Rarity: Uncommon Cost: {2}{B}{B} Enchant land

that player sacrifices two lands

Set: Portal Second Age Type: Sorcery Rarity: Rare Cost: {3}{W} Destroy all lands

you may put Nether Shadow into play

Set: Double Masters Type: Legendary Creature — Dragon Skeleton Rarity: Mythic Cost: {3}{B}{B} Flying