That isn't his weakness, Itachi caught him in it cause he was clueless.sasuke, since orochimaru's weakness is genjutsu. sasuke catches him in one and amaterasu would finish the job.
Yeah because Keeping susanoo up and Spamming its attacks cost no chakra at all. :|EMS low diff.
Oro doesn't have the speed to avoid ama-arrows.
Oro has nothing to penetrate susanoo.
Oro can survive at the very most 8 ama-arrows via body-vomit (forgot the name), and sasuke can launch arrows all day.
wft this must have been bakk wen u were hating man, MS would lose to OroMs sasuke will defeat prime oro with mid difficulty.
Hope you can what im trying to say
same way Sasuke did, ppl forget he used Oro's technique to surviveAmaterasu would end Oro easily I dont see how he would win