MP zerker

Delirium - Reverses your total pool of MP (if you're sitting on 3k MP, you now have 7k MP, or if you're sitting on 9k MP you're now down to 1k MP)

Darkside - While 50% or below your total MP, the dark knight draws on their bloodlust and anger to grant them 15% more damage and alters skill abilities.

Dark Missionary - regular effect: 10% magic mitigation, darkside effect: deals a large range aoe dealing 50 damage per target and pulling them directly to the user on use, stunning for 1 second.

Inner Shadow - regular effect: becomes the new target of any mobs aggro'd onto you for 10 seconds with 25% of your max hp, darkside effect: what it is now with your shadow fighting with you.

Quietus - MP per hit, give it back >o>

Abyssal drain - regular effect: heals with a cure potency of bla bla bla per mob hit, darkside effect: doubles in potency but 50% less for remaining targets etc etc etc....



Something along those lines. Where you have to manage your MP gauge still but you're in control of why you want to and what situations call for you to need more damage output or more mitigation.