This build is pretty effective as of patch 2.6.1. Playstyle is fairly basic - Keep up Wrath of the Berserker, Ancients and both shouts, use furious charge for at least 5 stacks of the R6 bonus and line up a seismic slam. Seismic slams are you main source of healing, so if you are close to death you can slam spam for survival purposes. The bulk of damage mitigation is handled by the Band of Might legendary ring effect (80% damage reduction for 8 seconds after furious charge) so don't forget to use furious charge at least once every 8 seconds.
With this setup you have to be careful not to spam charge when there are between 2 and 3 enemies left - you will stall your furious charge damage. This is part of the reason the ancients fury shoulder is cubed - if you stall the ancients will still generate fury for you for healing purposes. Since furious charge is your primary source of damage reduction, it's important to use a Diamond in the helm socket to bring the furious charge cooldown to 8 seconds even if you screw up and stall.
If you find yourself in a stall, it is best to just go find more mobs. If more mobs are not an option you must instead work to isolate just one elite and aim your charge to end on one enemy rather than passing through 2 or 3 and re-triggering the stall.
For rift lords you just want to machine gun spam charge and drop 5 stack slams right on their head.
The majority of your damage comes from rumble ticks, which occur 2 seconds following your slam at the epicenter of wherever you had targeted - these can crit for 15 trillion during the physical cycle of CoE and the 20% area damage provided from one rumble tick and BattleRage/Bloodshed will proc 3 Trillion damage as an AOE. Area Damage stat is pale in comparison to direct damage due to the incredible scaling of rumble ticks. This build naturally scales very well with mob density and struggles in single target situations - so focusing on area damage as a stat has a negative impact overall compared to direct damage stats. (AD does not deal damage to the original target that it triggers from, IE the Rift Lord)