Living dead is a pain to use considering its supposed to be DRKs OP button. This is mainly because of walking dead killing you and you having no way to combat that without a healer.

So my suggestion would be to make walking dead as much a buff as it is a debuff. When you enter walking dead you gain a 50% damage increase and all MP costs are reduced to zero. This would allow you to go into grit (if not already in it) and spam dark arts souleaters at no cost. With the increased damage which more than negates the grit penalty and bloodbath cross classed you'd be able to heal a large chunk of hp on your own possibly enough to remove walking dead with your own self heals.

The way I picture it (lore wise) would be your darkness going out of control because you are too weak to keep it in check, making your dark powers far stronger but obviously killing you if you don't get it back under control by recovering your strength.

This would make living dead much more desirable to use both as an invincible and just as a risky damage increase (which DRKs are known for in their old glass cannon incarnations).