Pray to the Fire Gods

Pray to the Fire Gods deals X damage to each creature and each planeswalker where X is the number of incantation counters on it.
Discard a card: Put a number of incantation counters on Pray to the Fire Gods or remove a number of incantation counters from Pray to the Fire Gods equal to the converted mana cost of
the discarded card. Any player may activate this ability but only if Pray to the Fire Gods is on the stack.