I don't entirely agree with your conclusion- Madara has his desire alright... lol- but nice job and Rep for you.Perhaps people haven't realized it due to the difference of their personality but their paths are scary similar.
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They both seek greater power and their masterminds..
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Who is a greater villain?...
Isn't that obvious? Orochimaru is the kind of villain you only see once in a couple of decades. Of course this is only my opinion.. I think Madara lacks: Tenacity, desire, complex personality, dement mentality and the scent of being a total alien when not really.. Madara is just enjoyable to watch him do his actions and manipulate but hes just not Final villain quality in my book.
So, with all the similarities in their paths threw the manga, it seems like there isn't enough room in the manga for both of them.
Madara is cunning but lacks the intellectual thinking of orochimaru. Oro was a sanin for good reasons. Unlike Madara Oro was more smooth. He was definitely more complex character. He wanted power and everything related with it just like Madara. But unlike Madara he didn't get anything free.