Sharingan CAN'T break genjutsu, -_-.......and did you not heare what Itachi told kakashi? he may have the sharingan, but only one with uchiha BLOOD can resist/break tsukyomi, Nagato had a implant, Madara is the true heir to the eye with the blood, he cannot break it......if rinnegan is a evolution from sharingan and sharingan can break genjutsu wouldnt rinnegan also be able to do it? otherwise it would seem more like a degradation