Ebonstone Vault

When you draw Ebonstone Vault, put it onto the battlefield entrapped under your control. (Put it
onto the battlefield face down as a 0/1 Mine artifact creature with defender and "When this creature would
die, instead turn it face up and exile it. If it is
a nonland card, cast it without paying its mana cost." Players may not look at the card while it is face
down.)
{t}: Add {b} to your mana pool.