Im wearing 1 ring instead of 3 piece or 2 + 1 RORG for the elite bonus damage, Not for the damage reduce, even though i have a 480+ str 6 AS 6 CC 49 CHD RORG.
Mara amulet is because, i can go as low HP like 250k and use item without resist or vit, i can go skill dmg and high str without vit. Since im low on resist and his poison heal me too fast.
Im even killing him at around 6 -10 sec. before my valor runs out.
Yeah that's why i deleted my stupid questions, i misread you completely. Your damage is sick indeed. Not getting that high, but i found a way to get close.
So after fiddling around all day i can final share my set-up and be actually useful

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Here's my lightning furnace build for 11 sec ghom (always precise 9 sec left)
Augchild shoulder,helm,bracer - Furnace - Lidless - Tyrael (%demons works on ghom) - unity - soj - thundergod - (rest your choice)
= 1.5 mil unbuff , ~50% elite damage , ~70% lightning damage , ~15% to demons + some extra blessed hammer damage (boots,helm)
Skill: Blessed hammer thunderstruck with provoke charged. Laws of valor critical. Akarat firestarter. Heaven's fury (lightning) and Falling Sword (lightning) these last 2 are free of choice, but these work well.
Passive: Blunt, Finery, Holy Cause, Heavenly Strenght
This gives you lower damage then foth but a higher proc rate of furnace + firestarter. Heaven's fury and fallings sword won't speed up things much damage wise, but do seem to help out getting firestarter and furnace get started right away. They both do dot damage that stack with provoke charged i presume. So when you start casting hammers the damage is already build up.
Using the face-tank instaleave i get about 65 games/hour.