Note Asajj Ventress is wielding a yellow light sabre, the color normally used by the Sentinels.
In the Fantasy Flight Games tabletop rpg, there is a sub-class of Sentinel called the Shadow Sentinels, who specialize in hiding their force connection from other force users, and hunting Sith relics and Lords. It will be too cool if Ventress’ redemption arc makes her into a Shadow! My favorite class.