Arkis Wode

This guy leads the Schism Collective. He's most notable as one of Malgus' lackeys during The False Emperor flashpoint. (He's the one who sics HK on you.) You can kill him or spare him for LS points. Regardless, given that he spends half the Flashpoint telling you that he's going to kill you, he surrenders awfully quickly. Then he bitches that the Republic didn't respect his genius and the "old" Empire didn't respect non-humans. Hence he wound up with Malgus.

Vell Narroc

Vell technically worked for the Republic, but was leading one of their most corrupt projects : The Power Guards on Nar Shaddaa from the Jedi Knight story. He defends the practice, considering the volunteers "heroes". Regardless of affiliation, he is not a credit to his species.

Voklov Adaim

Voklove doesn't appear on screen, but he's scheduled to be executed for developing bioweapons. I don't know if that says more about himself or the laws and traditions of his homeworld.

Jarak

Finally, a man who needs no introduction : Jarak spent years tormenting Vaylin to install her mental blocks. He's a first-rate monster. (Later, we find out he also tortured Felix Iresso.)