This is my favourite all-rounder character to play at the moment - Very high AOE damage, very good survivability. Lots of fun to play, very well stylised. Everything I love in a character. The build has 100% Vitality and Chaos to Aether damage conversions, making Oblivion a perfect relic to use.
The amount of proc damage from the sword, the Bonemonger set, the rings, the devotions etc all significantly boost the damage of this character. High weapon damage on a fast, long-ranged and AOE attack like Oblivion means you’re full healing with most attacks. Inquisitor Seal and Mark of Torment help to mitigate damage. Eye of Korvaak devotion proc helps to provide CC against nearby enemies with petrify, further mitigating damage, and debuffing their OA/DA as they get near. 
Grimtools: https://www.grimtools.com/calc/nZo8Y5EN
An MI belt has been used, but the specifics of it are not required for the build; Balance the resists out for whatever resists your MI gives you. What’s more important on the MI is a good Vitality to Aether conversion.
Here are some videos of playstyle:
Enjoy.