I was looking for a way to make a lot of endurance charges and I came upon crit BV Hierophant.
by my calculations I should be able to achieve ~180k dps with level 20 gems (no quality), a 6l voll's protector, divinarius and rathpith globe, as well as maligaro's virtuosity. It could be more, right now I'm theorycrafting with an Added Chaos Damage Support gem but with the current damage effectiveness for Blade Vortex, if the damage effectiveness is adjusted upward to match the base damage that value will improve, also it might be better to use a different gem if the damage effectiveness is not increased, It would be nice to keep it blue without taking controlled destruction though so that I could swap in faster casting in areas where the damage is less relevant, enabling me to clear faster by spending less time casting.
From there at level 85 I should have >5700 life with > 1000 ES and a 10% mana shield while being able to rapidly stack 8 endurance charges. That's without considering any sort of GG Rares or anything of the like (although I used fairly high rolls for my unique calculations)
from the tree and the gear i'd have ~61% crit chance. At that crit rate, if I'm maintaining my BV stacks it should be very easy to rapidly generate endurance charges, even against a single target. It's far easier in packs too.