Ignis, The Phamton Knight

Ignis, The Phamton Knight cost {x} less
when {x} is the Rakdos Counters that
you have
Sacrice a creature, you gain Rakdos Counters
equal to the mana cost of the creature sacrifice.
{8} All creatures gains -x/-x when {x} is
the number of Rakdos Counters this
ability dosent affesct to creatures Spectral