Classic

This enchantment enters the battlefield
faced down. Whenever an opponent says
"its your turn" or "tisi", you may pay {3}{b},
If you do, each opponent exile to the shadow
realm the top 3 cards of their library,
Then flip this enchantment face up.
{1}:cast a card from the shadow realm,
you may spend mana as though it were
mana of any type to cast it.