Chapter 676 has a subtle but significant plot hole when examined. Madara stabs Sakura, while she is in Strength of a Hundred Seal mode, which in a nutshell is self-healing and super strength mode, with one of his Yin-Yang rods, rods which also have the ability to negate any form ninjutsu. But when she retreats, she was able to heal herself. How in the hell was that even possible? It's even more jarring when you put into context that the exact same thing happened with Tsunade, although in that case, she was stabbed by Madara's Wooden Susano'o sword so it's justifiable that she would not have been killed. But Sakura... no. She should have died, plain and simple.