Board Thread:Boruto Discussions/@comment-1458758-20171229124917/@comment-33953813-20180101190251

Considering Ao, he wasn't such a good shinobi from the start in terms of moral standards since he practically stole a Byakugan after defeating the Hyuga member and I don't think that he in any way deserved it since it not honourable for a shinobi to meddle with an opponent once he has been defeated. Ao was the first to do such a dishonorable act (well apart from Danzo but he is dead and Orochimaru isn't a threat at the moment). No other shinobi stolen a Byakugan or Sharingan from a fallen Uchiha/Hyuga shinobi.

Also Ao still has bloodmist shinobi vibes in him since he also had had to kill his best friends to get a higher rank in the village. So I'd say he is pretty ruthless and couldn't care less about shinobi peace.

I think he volunteered in the war only because bit was his duty and orders from the mizukage. I am pretty sure that he didn't like the idea of uniting the 5 nations especially after discovering Danzo's genjutsu on the other kage.

So now he just wants all the 5 nations to fight again and that's why I think he joined Kara.