I've been thinking of this for a very long time now. I think since back in itachi V sasuke, I was thinking "what if itachi and sasuke are both madara's grandchildren"?. It'd explain why they're just soooo damned OP for uchiha. Itachi, Sasuke and madara are in a completely different league of uchiha on their own... It'd make sense that itachi and sasuke inherited their power from Madara. In fact, madara stated that "among the uchiha clan, he was born with an exceptionally strong chakra like never seen before", then kyuubi stated that sasuke's chakra(before MS) was as dark as madara's.
Well why we're his parents so weak?
Power can skip generations.