getBonusValue

The passive damage reduction applied to incoming damage.

This is the single source of truth for the skill: the generic PASSIVE branch in com.magmaguy.elitemobs.api.PlayerDamagedByEliteMobEvent applies this value directly as damage * (1 - bonus), so it must already be the final reduction rather than the raw scaled value. Flat DAMAGE_REDUCTION, still run through the shared defensive clamp so it can never negate or invert incoming damage.