Withering Time

If creature dies, each creature gets -1/-1
until end of turn.
If creature dies, its controler draw a card.
If creature card is put into a graveyard from anywhere, its controler add X black mana, where
X is that creature power. Spend this mana only
to cast an creature spell. Until end of turn, this
mana doesn't empty from your mana pool as
steps or phases end.