Virtues

Devoted fighter would be a good place to start. Go pure Devoted or multi-classing with either Paladin for more tank or Soul Blade for more damage. Soul Blade in particular works well because Soul Annihilation is only a primary attack.

I'm pretty sure if you are ever detected in the Mansion without wearing the robes the place goes into alarm (you can hear the bg sound when you first load a new area in the mansion). After that, you have to carve a path murder hobo style.

Here's my first try at one of the images from that big pack from PoE1. Kind of a pain to do.