Mana Vault
Artifact
Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay 
. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
: Add 
.
イラスト：
Fifth Edition#388レア英語