Excellent guide! I used it to build my now 49 Ninja Blade/Ninjitsu. I took blinding powder, Avalanche in addition to all of the defense stuff.
I took Mako's Waterspout and luv it. It's slotted with no damage but stuns and defense debuffs and I rely on it a lot. I think I wll take caltrops at 49 thinking it will make them try to run and attack less.