There are two variants for this build and depending on preference: Grim Scythe (stable dps) or the Devour (burst dps)
Briggs' Wrath + Avarice Band+ Goldwrap + Boon of the Hoarder + Frailty Aura of Frailty +Life from Death creates a giant aura (that is almost the size of the screen) to pull all the enemies towards you, to paint an easy target for devastation.
 
Skills:
Grim Scythe variant:
Grim Scythe Cursed Scythe Corpse Lance Brittle Touch (single target burst) or Corpse Explosion Close Quarters (multi-target burst) Bone Armor Dislocation Blood Rush Potency Land of the Dead (I prefer Frozen Lands to stop goblin hoards) Frailty Aura of Frailty Devour variant:
Devour Cannibalize Corpse Explosion Close Quarters Bone Armor Dislocation Blood Rush Metabolism (Speed) or Blood Rush Potency (Survivability) Land of the Dead Shallow Graves Frailty Aura of Frailty *Note: Corpse Lance isn't recommended for this build. Also this variant is better playing with a team is because it's a double edged sword, it's easy to have the flow stop when there aren't a good supply of elites coming your way and you will feel like you're dead in the water. However it is a choice for the Grim Scythe build due to the consistent damage that grim scythe itself can deal.
Passives:
Stand Alone Spreading Malediction Life from Death (Survivability) or Blood is Power (Additional CD reduction) Swift Harvesting (Grim Scythe) or Blood is Power (Devour) - Until the bugged Fueled by Death is fixed  
Items:
Weapon: In-geom
Off-Hand: Leger's Disdain (grim scythe build) or Lost Time (speed)
Set: Inarius's Conviction + Inarius's Martyrdom + Inarius's Perseverance + Inarius's Reticence + Inarius's Understanding + Inarius's Will
Necklace: Wisdom of Kalan
Belt: Goldwrap
Ring #1: Krysbin's Sentence
Ring #2: Avarice Band or Briggs' Wrath (whichever rolled better)
*Note: For your items, I suggest getting additional gold/health glob pick up area to add to the passive affects that we're wanting to boost
Kunai Cube:
Trag'Oul's Corroded Fang
Avarice Band or Briggs' Wrath (whichever wasn't rolled very well with)
Aquila Cuirass or Grasps of Essence (depending if you're using corpse explosion - also note I suggest adding Flawless Royal Diamond to some sockets to add some resistance if you're giving up the damage reduction)
Legendary Gems:
Bane of the Trapped
Boon of the Hoarder
Gogok of Swiftness (Grim Scythe) or Wreath of Lightning (Speed)
Gems:
Helm: Flawless Royal Diamond
Everywhere Else: Flawless Royal Diamond (Survivability) or Flawless Royal Topaz (Damage)
 
Rotations:
Grim Scythe variant:
Keeping Bone Armor on cooldown, this is the most important thing for this build to work because of the damage reduction and damage boost you get for the set bonus Corpse Lance/Corpse Explosion is used against the champions, rares and uniques. Land of the Dead will be used when during large encounters/boss fights. Blood Rush will be used for traveling/utility (especially when In-geom is procced). Grim Scythe will be used in all other cases. Devour variant:
Bone Armor (keeping on cooldown), to get things started. Land of the Dead to start building your momentum when your 1st elite pack shows up. Corpse Explosion  you'll be using as your main point of dps because you'll be dragging everything on the screen towards you, piling towards the center to deliver devastating splash damage. Blood Rush + Devour in sync will be used as your movement utility, which during your In-geom proccing will make Devour almost needed because of how quick you'll be moving and how quickly your health will drain. -----------------------------------------------------------------------------------------------------------------------------
Reference for a standard ancient only build: https://www.d3planner.com/236420675
Reference for a perfected build: https://www.d3planner.com/376141709