So, can he deactivate his eye or what. It's not like it was transplanted. He sorta has Asura's chakra because Rikudo chakra is (in essence) Asura Chakra + Indra Chakra.
Madera can deactivate his Rinnegan, so why can't Sasuke?
Madera can deactivate his Rinnegan, so why can't Sasuke?
Once you reach the ultimate Dojutsu, you have to keep it that way forever.