I've just made a ninja-archer who is insanely powerful (Archery, Tactics, Anatomy, Healing, Ninjitsu, Hide, Stealth, max Str/Dex). I've got him in Horrific Beast form and a Darkwood suit (HPR 36) with a total of 60 DCI and 147 HP and 4 sec bandages and all-70's resists (even when Corpse Skinned), so he's super-durable even against the gank. Whenever I get to red health I just drop a smoke bomb and let my HP fly up. Haven't died yet.
On offense, I just Dismount a guy and then switch to x-bow and Concussion him to death, along with Shuriken/Darts and Melisande's Fermented Wine (can also go back to the heavy and Moving Shot him to death if he flees). Sometimes it's fun to use a Shortbow against a bunch of spellcasters and spam Lightning Arrow (constantly disrupting them).
All in all, a very fun template to play, and quite powerful. Ninjitsu is far from dead, but I think you need to be creative to build effective ones (I have a pretty sweet Ninja Tamer with a 120 Reflect Physical suit too, though he's too gimp to ever actually play).