We all know madara to be very powerfull ninja.
ofcourse he had some pupose !!!
I thing he is true leader of Akustuki becouse we all saw hem to make kindi comandmens to pain . And I think it`s he to told pain to go and find 9t.
He told sasuke about Itach`s life. About konoha and many other.
He told ssasuke to take itach`s eyes .
What is hes purpouse.
I don`t believe he want to destroy konoha to revenge , if so he`ll simply tell pain " go and destroy konoha with your shinara tensei"...
So whats for madara ???