This is a tanky Conjurer build using poison as main damage, vitality as secondary damage. He also has ~32k over 5 seconds poison retaliation damage.
Enemies foolish enough to strike the Noxious Avatar of Dreeg will be poisoned to death!
(v1.0.0.2) Updated devotion, changed skill a bit to have 1 point in Doom bolt.
Grimcalc w/o +skills (with devotion):
http://grimcalc.com/build/mznwUy
With + skills:
http://grimcalc.com/build/jz1Msy
Ultimate Fabius kill in v1.0.0.2. Used ~ 40 seconds to kill him. Got shadow strike by him once and nearly dead lol.
https://www.youtube.com/watch?v=cZtEkz8a01I
Ultimate Log kill video @ level 79 (also shows my gears): (v1.0.0.1 old version)
https://www.youtube.com/watch?v=ieIiMmPw-u4
I stand very close to Log so he can melee attack me and taking the poison retaliation damage. 100% facetank the entire fight.
Play style:
Chaos strike (from the rift stone component) into a pack of enemy and let them melee you and take the ~32k over 5s poison retaliation damage.
Cast skill on tougher/ranged mob to kill them.
Notes on gear
Shroud of Dreeg set is BiS but only if you get 5/5 pieces, otherwise the gear choice shown in my video will give better +skills and retaliation damage.
If you don’t have Nidalla’s Legwraps, Empowered Soiled Trousers is good too for the poison retaliation damage.
Can consider using a good Badge of Mastery instead of Undying Oath, you can still get 26/16 Blood of Dreeg, but I think that Undying Oath’s proc does contribute a portion of the damage (maybe 5%) especially in boss fight.
Other note
The tooltip of Possession says you allow your body to become a vessel for the witch god Solael, but I believe Solael and Dreeg are good friend so nothing theme breaking here.