It seems that the tension between Shukaku and Kurama that Gyuki alluded to is still existent. Although it seems to have taken more of a competitive nature instead of being fueled by resentment or jealousy. What a nostalgic scene that was between Shukaku and Gaara. Already they seem to be capable of cooperating with each other as partners like Naruto and Bee with their respective bijuu, even when they're not sharing the same physical shell.
As expected, Tobi was going to resign himself as a sacrifice for a wide scale Rinne Tensei resurrection. Oh, but the twist ending with his intentions suddenly being impeded by Madara and... Black Zetsu! I thought he might make a reemergence onto the scene, but now that it is actually happening, it's saddening to see how he's being manipulated by Madara. A construct of Madara's will until the very end. He admitted it himself that his relationship with Tobi doesn't override the will of his creator. The expression he had on his face, the shock, it's like he's horrified at what is Zetsu doing to him.
Tobi is selectively deciding his own fate which may appear self-centred or egotistical, but it is consistent with how his character has been portrayed since the fight began. His mindset is tunneled by his memories of Rin. Even with Kakashi's words echoing in his mind, Rin is still in the back of his mind. Moralistically it's selfish, perhaps even cowardly, but I can personally respect a character who chooses to seize their destiny by their own hands and die in the way that they choose. As a villain it can make them more compelling.
Madara was defeated in a quickly fashion. Of course he didn't intend to be sealed. Still, I thought he would be able to hold out for longer than he did. At least the story is progressing now. Madara is being resurrected and he's losing his immortality as well as the infinite supply of chakra and regeneration. That doesn't seem very practical but he was in a pinch just now and it apparently freed him from Hashirama's Myoujinman. Still, the entire Alliance has him in their sights now. What will making himself mortal accomplish?
Sai was very impressive this chapter. We haven't seen much of him lately and to see him take centre stage like this was refreshing.