This is the endgame build (filled with expensive/rare mods) I typically run for solo endurance survivals or arbitration where I need the maximum possible damage reduction/survivability.

The goal here is simply to hit the power cap of around 214% for [Shield Of Shadows] to create the maximum number of shadows and therefore provide the maximum of 90% damage reduction.

[Adaptation] pushes this to 99% and [Health Conversion] is probably just overkill at this point. Keeping duration, efficiency and range at 100% helps round off the build so you don't have energy management issues when it comes to recasting [Shield Of Shadows] or firing off terrify in a pinch.

I used to run [Blind Rage] with half efficiency but there have been several times where the energy regain just hasn't been fast enough to recast shadows, and in something like arbitrations, you really don't want to be caught with your shadow pants down.

Hence I switched to [Energy Conversion] + [Umbral Intensify]. [Energy Conversion] is basically always active due to desecrate.