They cant even be compared, Shisui its a 9/10 ninja. Top tier ninja without a doubt. Ao its a 5/10, a support ninja that is a rare in sage treasure and common on kage. The way that Top tier ninjas have been given away in rng event doesnt make much sense in my opinion, and its making them lose some value with it. When a rly solid ninja that costs around 15k minimmum its being given out so often for such low price its just a way to make those who got it interested in the game, giving them a reason to enjoy the game. While people who spend are paying for those ninjas the ammount they are acctually worth. Anyway i know i went a bit off topic but answering you question, get Shisui man, he is great and if you keep playing you will get Ao for free anyway.

Mangetsu chojuro mei water main is way better man. You cant seriously expect Ao to be a meta ninja right now, his days are long gone. And when you compare him to shisui... is just a sin tbh

At first i was like, wtf is this guy talking about... But then you got me with Venezuela server, 6 stars and robotic arms ahahahah nice one considering how troll this whole thread is, too bad some people didnt see it as a joke