Grahv is a Nikto who fights wholehearted for the Rebellion. His skills as a sniper are in demand and he loves to use them. Give him a handful of grenades, a good blaster, and a place to wait and he will have the time of his life!
He is also a follower of the Morgukai, trained to notice when others use the Force and to kill them. This is his one abiding passion, above even the strength of his passion for the Rebellion. This puts him in a precarious position with Vestige, once he notices that she is Force-sensitive (and notice he does).