Board Thread:Naruto Discussions/@comment-25188745-20170620121006/@comment-27916438-20170620131443

@Starscream1998 Hashirama actually casted a rank-A genjutsu ,i'm Pretty sure that him and kabuto are the only characters in the series that had done so,and also used the rashomom gates against Madara and was also skilled in barrier jutsu, fūinjutsu and bukijutsu.

My guess of why Hashirama was so skilled is because he has grow up in the warring states and was forced to fight all the time,so he had to learn faster compared to the other Ashura incarnations. Could be very well that there was some indra incarnation that was unskilled as well,who knows.