A very exciting chapter. So this chapter has confirmed that Madara was indeed manipulating the Fourth Mizukage, Yagura. It seems that Madara has the ability to take away peoples' free will, similar to a technique Shisui possessed that Ao mentioned during the Five Kage summit.
What's interesting though, when Madara "acts" as Tobi, he's always wearing a mask, and his hair is cut short instead of the style we see when we fought Hashirama or met Itachi, or even now controlling the Mizukage. But as himself, Madara did not appear to be wearing a mask when showing his face to Kisame, and his hair is long and flows down past his shoulders, but for some reason in chapter 404, Madara says he deceived Kisame, and shows him his face again. Could Tobi and Madara be two different people? While I don't think it's likely, it could be possible.
And as for Kisame, it seems he's broken free from his shackles, but I don't think he has very long to live, but of course I could be wrong. I think that last act was highly symbolic of the fact that Kisame has broken free from the chains of lies in this world, and has finally met the truth that Madara has given him.