The problem is if you give him any more team support at all he will break early-mid game with his ability to smash ganks. He can already save people from just about any gank, give him a castable shield or some other CC/utility? Forget about it.
IMO he needs something damage related as a W. Make him a threat because he has higher damage output than most tanks and he will be a good choice again. Would fit with being a ninja too, I guess.