This.
I applaud you for going Dual Damage (it is feasible to spec for! 
), you just need to have some form of sustain to get this build going in Ultimate. I would second the suggestions to move points into Mogdrogenâs Pact and to perhaps spec heavily into Health Regeneration to help survive. That would entail moving Devotions to Behemoth and Lizard (with perhaps more such as Harvestmanâs Scythe) and getting a few Gollus Rings to push Mogdrogenâs Pact into higher levels.