Claw Stalker for PVP.
Copycat uses her stealth training and mutant ability to alter her appearance to make a living as a cat burglar. Well... Assassin is probably a better word. She likes to assume the appearance of others and let them take the blame for her killings.
PVP build for level 25 (Bloody Bay). In this build I can only pick three powers from the secondary (except hide). This would probably be melee def, ranged def and status protection. Since the Endurance cost is lower for the SR toggles, SR is probably better than Ninjutsu.