mana crypt-vault

Mana crypt-vault doesn't un-tap on un-tap step
At the beginning of your upkeep, you may pay {4}
At the end of your upkeep, if Mana crypt-vault is tapped, it deals you 1 damage
During your upkeep, flip a coin. If you fail, mana crypt-vault deals 3 damage to you.
{t} add {5}