One Sith

One Sith Remnants, The Long Conflict, Kethenites, The Golden Host, and the Keepers of the Sith Code.

Types of characters that work well here:

The Keepers of the Sith Code, The Kethenites:
Keepers and Zealots of the Sith Code.
Fanatics of the Long Conflict.
Echani Loyalists.
Apprentices of any One Sith Members or Masters teaching.

The Golden Host:
Sith and those Driven to Golden Glory, Riches, and Vanity.
Religious Zealots
Sunguard Members.

All:
Monsters and Experiments of all kinds.