Fatal Push (Borderless) [Secret Lair Showdown] Cephalid Advisor Set: HeartGold & SoulSilver: Undaunted

Set: HeartGold & SoulSilver: Undaunted Type: Darkness Rarity: Holo Rare Retreat cost: Colorless

{T}: Add {B} for each Swamp you control

as if it had always known

Shatterskull Pass is a pretty distant second

Set: From the Vault: Exiled Type: Artifact Rarity: Mythic Cost: {1} {1}: Look at the top three cards of your library

Fatal Push (Borderless) [Secret Lair Showdown] Cephalid Advisor Set: HeartGold & SoulSilver: UndauntedSet: Secret Lair Showdown Type: Instant Rarity: Rare Cost: {B} Destroy target creature if it has mana value 2 or less. Revolt Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.