Blasphemous Prateor Rykard

Trample

{b}{g}{u}, Sacrifice X creatures: Monstrosity X (If
this creature isn't monstrous, put X +1/+1 counters
on it and it becomes monstrous.)

When Blasphemous Prateor Rykard becomes monstrous, instant and sorcery spells in your graveyard gain flashback until end of turn. The flashback cost is equal to its mana cost.