Nidhogg!?

[Jinko]

They could do it so that you have to quest for an item that must be worn or else the nm would kill you every time, maybe after the item is used a few times it breaks and you need to get another. This would add a level of complexity to the fight!

There were quest bosses in WoW that you would have to use a specific item on them to lower their level so that you could defeat them.

Say for example in this case, boss is always up but lvl 99 and you have to use an item on it to weaken it.

I agree with the above about quest chains, I don't want leves though as leves are fundamentally broken in that if you DC you fail the leve etc.

Quests something similar to the Job quest line but agree that it should be difficult.