Now that I recall when Kyuubi told Sasuke that his chakra or whatever was more sinister than his own, that really ticked me off. I hated how much Kishimoto overpowered the Sharingan, and tries to add so much depth to it now. The Sharingan branched off the Byakugan, but it just completely overwhelms it. It's such a huge deus ex machina plot device now, that it's kinda annoying.