Hi,
I am creating a major ongoing antagonist for the PCs. As I am new to the system, I'm stuck on career and specialization.

She's a Sith Sorceress who is obsessed with controlling her environment including the people around her. While she can use a light saber her primary attack and defense modes are spellcasting. She also has minions to do her fighting for her.

Any suggestions on the best career and specialization for her?

For NPCs, you're best off not bothering with Career and Specialization. When building NPCs, you can give them whatever Abilities, Talents, Skills, and Characteristics you want.

6 hours ago, P-47 Thunderbolt said:

For NPCs, you're best off not bothering with Career and Specialization. When building NPCs, you can give them whatever Abilities, Talents, Skills, and Characteristics you want.

This.

I believe F&D has some good rules on creating nemeses (let yourself be inspired by the Inquisitor rules), and the EotE GM's Kit has some additional stuff (unless that was all included in F&D). Disciples of Harmony also has some cool rules for mentors, that while isn't designed for a nemesis, could easily be used for that too - as an inspiration at least.

Indeed. Careers and Specialisations are strictly a player character only thing.

Han solo doesn't doesnt have the Smuggler career, Boba Fett doesn't have the Bounty Hunter career.