where is he ?

and do i need a quester ?

when farming occy is it ok to turn in the quest? or by turning in the quest will it make me so i cant farm it?

I think you must have the quest. I have tried after finishing it, and when the fernicle popped, I got nothing

Havent really farmed anything but Shulgoth so far, and nothing special really, mostly those worthless mind control weapons.
Anything special you have to do to be able to kill Wurm/Abbadon more than once (like occy)?

crap because im to bad to solo it on normal.

look for runs

i do them my marksman still has the quest so all i have to do is have an evoker discard of the corpse using cleansing and i take a prd to town then pp back to angel passage and et voila!