Originally Posted by Qwertystop
So how do I put it in? Just say "The cost to resist this is an amount of willpower equal to the Shatterer's Essence rating"?
But that answer is too short, so have a longer one:
Yes, although you could also say "Victims may spend a number of willpower points equal to the Shatterer's (Essence) to resist this effect, to a maximum of five willpower."
(5 is the max anyway.)