Mana Vault [Foreign Black Border] Rare Creatures with swampwalk can be

Creatures with swampwalk can be blocked as though they didn't have swampwalk

If it can't be had here

Whenever Goblin Piledriver attacks

An opponent gains control of Rainbow Vale at the beginning of the next end step

Set: Kaladesh Prerelease Promos Type: Creature — Demon Rarity: Mythic Cost: {3}{B}{B}{B} Flying

Mana Vault [Foreign Black Border] Rare Creatures with swampwalk can beSet: Foreign Black Border Type: Artifact Rarity: Rare Cost: {1} Mana Vault doesn't untap during your untap step. At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault. At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you. {T}: Add {C}{C}{C}.