Buy @ TCGplayer
Cumulative upkeep—Pay {B} and 1 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
If a land is tapped for mana, it produces {B} instead of any other type.
This effect changes the type of mana produced, but not the amount. For example, if a land that’s tapped for mana would add {W}{W} to its controller’s mana pool, it adds {B}{B} to that player’s mana pool instead.
