Board Thread:Naruto Discussions/@comment-43776375-20190909151313/@comment-32685487-20190909235453

You can switch Dojutsu from Rinnegan, such as Madara's clone switching from Rinnegan to Mangekyo Sharingan in order to use Genjutsu on 4th Raikage. Rinnegan and Byakugan are seperate dojutsu so switching from Byakugan to Rinnegan and back and forth is simply them switching from one dojutsu to another dojutsu. It seems that in Sasuke's case his left eye's EMS has merged with his Rinnegan, so he cannot turn the left eye off. Shown with Kakashi he cannot turn off the Sharingan he can only advance it into the Mangekyo Sharingan. As shown with Nagato even the first time he activated the eyeballs they skipped past everything else to Rinnegan and since he had no memory of the eyes awakening his eyes went back to normal.. then when Yahiko was attacked he awakened them again and they stayed awakened, but he could never access the Sharingan, or the Mangekyo Sharingan and he could never turn the Rinnegan off while seemingly it took no strain on him at all.