Only Negated Advantage enhancements that reduce unnatural fortitude

Only Negated Advantage enhancements that reduce unnatural fortitude is a special limitation designed to create a Limited Enhancement when applied to the Variable Enhancement enhancement used for affliction (advantage)
It is used for Slayer's Strike on page 10 of Monster Hunters Power-Ups 1
It reduces the usual +1500% of Variable Enhancement 150 (150% worth of enhancements) to +750% by being priced at -50%.
This is likely derived from the similar approach taken when designing Modular Abilities which are limited just to Afflictions, or even more particularly to Afflictions which provide certain modifiers.
In either case it allows a lot of customization for afflictions.
By taking off the "that reduce unnatural fortitude" it would probably be worth far fewer points, such as -40% or less.
category:Limitations