I'm doing the Jabba's palace missions, but I'm stuck on a part where I'm supposed to kill the four "Valarian's assassins." For some reason I keep getting defeated. I'm a level 20, and the NPCs are level 18. I've noticed that the three I can't kill have this claw symbol wrapped around the NPC level indicator. The one I had no trouble killing did not have that symbol.
Is there any trick to this? Does anyone know what that symbol means?