Board Thread:Naruto Discussions/@comment-24347194-20150212224652/@comment-1018594-20150213003904

Like GodlyHades said, Sasuke's Rinnegan was most likely specifically designed to grant him access to his Sharingan abilities without having to switch back and forth. Since his Rinnegan also gives him unique abilities, it can be assumed that it was made specifically to let him defeat Madara/Kaguya and end the Infinite Tsukuyomi.