How to explain the Sith Inquisitor?

I could tell you that the Sith Inquisitor is the Emperor Palpatine to the Sith Warrior's Darth Vader, but that sells it short. The archetype is just inspiration. It's not the destination, or the road we take to get there, but the guide. The Sith Inquisitor is Raistlin. The Sith Inquisitor is Lucifer. The Sith Inquisitor is Julius Caesar. The Sith Inquisitor is what you make him.

When we set out to build our game, we knew we needed more than one Sith class. The original trilogy only has two Sith in it, but they couldn't be more different: the heavily armored brutal physicality of Darth Vader compared to the frail but immensely powerful Emperor Palpatine. When we extend our inspiration to Episodes I-III and The Clone Wars cartoons, Count Dooku, Darth Maul, and Asajj Ventress further expand our concept of what a Sith can be. Is a Sith a lithe quick fighter who uses the Force to enhance his/her physical combat prowess, a calculating deceiver adept at Lightsaber duels, or a master manipulator and amasser of dark side secrets? Does a Sith use one lightsaber, two Lightsabers, or a dual-bladed Lightsaber? Having multiple Sith classes allows us to embrace all of those Sith inspirations, instead of having one Sith class that was the jack-of-all-trades and the master of none.