Mana Vault [Ultimate Masters] Sliver Mutant if it's on the battlefield

if it's on the battlefield

Set: Antiquities Type: Artifact Rarity: Rare Cost: {4} You may choose not to untap Tawnos's Coffin during your untap step

Hero of Akros and at least two other creatures attacked this combat

" Saying nothing

Set: Vanguard Series Type: Vanguard Rarity: Rare Sacrifice a permanent: Return target creature to its owner's hand

Mana Vault [Ultimate Masters] Sliver Mutant if it's on the battlefieldSet: Ultimate Masters Type: Artifact Rarity: Mythic 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}.