L2J Server

Hello guys. I am curious for people to give me ideas how to nerf a list of mobs. For example i want to nerf all mobs in dvc and all mobs in soa. I know how to do it manually mob by mob but is there a way i can select a list of mobs and nerf them with lets say -40% on all stats?

Ive been thinking on creating passive skills that give -40% p.atk m.atk / p.def m.def and then add it to every monster i want to nerf. Is there a better solution or i start getting to work?

-% p.def and m.def its a bad idea since mobs already have low def i'm going to nerf -% hp instead to keep game balanced.