Archfiend Ivariai  

I'd hit it too.

you have to hit for the quest XD

Be careful if you have people in your group at different stages of Missing Mask.

We zoned and had one person who had killed Swinelord, Archfiend (this gal), and some of the dolls. The rest weren't even to the past of needing the Archfiend. We passed by the library (without going in) and she popped on us. We went ahead and killed her because I've heard people say you can't break an encounter in Nek Castle. So, by the time the rest of the group needed her for their quest we couldn't get her to spawn.

We tried logging out everyone but me (I had long completed this quest) and having them log back in. That did not work. Then we all logged out to see if by some miracle we would get a fresh Nek instance. Needless to say, we logged back in in Nek Forest, locked out for 16 hours 45 minutes.

So, just be careful pre-spawning her or you won't be able to finish the quest that day.