At the beginning of each player's upkeep, that player mills a card. Then they create X 1/1 black Minion creature tokens, where X is the milled card's mana value.
Mana cost
4
B
B
Mana value
6
Printings
From
$5.58
EDHREC rank
#15033
Buy
Formats
Legacy
Legal
Vintage
Legal
Commander
Legal
Rulings
1 Aug 2008
If the card has no mana cost (for instance, if it's a land), then its mana value is 0. This means no tokens will be created.