I use em in a Zaul sith team to be "the guy" who takes all the hits. Maxed out.. g11.
As such I need him to do damage.. so it's all Crit Dmg and Crit chance with speed secondaries. I got em to about 50% crit chance (which you will need outside of the first order synergy).
EP ability nukes a teeny bit of his health for free to allow him to OHKO some poor toon with his third ability for like 40k. If he can crit!