Board Thread:Naruto Discussions/@comment-25139119-20140722023329/@comment-23887466-20140722101249

It was noted that Itachi had a very powerful Chakra and Sasuke being his brother, he has the same, not only that but being Indra's reincarnation means that his reserves of Chakra is very high and special. The problem is that the Mangekyou consume too much Chakra and put a big burden on the body, after obtaining the EMS, Sasuke was able to use his Doujutsu more freely since not only the burden on the body is gone but the Chakra consumption isn't high anymore like the Mangekyou which enabled Sasuke to use his eye techniques like using normal techniques. As for the Rinnegan, in Sasuke's case, gaining the Rinnegan is different from Nagato's, Sasuke not only awakened his own but also received Chakra from Hagoromo while Nagato was simply using the Rinnegan with his Chakra as an Uzumaki.