What if Muu Turned out to be the Right Hand Man of Madara??
Wouldn't it be cool if Muu is evil and turned out to be Madara right Hand man??
Most people would think that Obito is the Right Hand man Of Madara but you guys are dead wrong!
Obito is simpily using Madara while Madara is using Obito at the same time.
So the right hand man of Obito is Zetsu
The right Hand man of Orochimaru is Kabuto
The right Hand man of Danzo is Torune
The right hand man of Ay is Darui
Etc, Etc, Etc!!!!
So to see a God of Shinobi have a Kekkia Touta on his side, that would be too Op.
Muu who's a sensory ninja type able to go invisible where no one can't detect, he could fly, capable of using Dust, Fire, Wind, and Earth Release and go on fragmentation state.
Imagine, Onooki will have major character development as how Muu and Madara always superior to him and how he would react if Muu is evil, and how he tend to fail in the past.
Onooki would've died by Madara to protect the other Kages, and I will have major respect for Onooki.
Tsunade should also be dead, but even though that occurs , that wouldn't make any difference for me to like Tsunade.