If the fight ended when shishui gg him you'd be here saying "shishui so badass. Shishui own danzo. Shishui 1 shot genjutsu king"To me a fair fight is when two opponents face each other on equal terms.No dirty tricks,no outside help,and no ambushes.
Danzo ambushed Shisui because he knew that Shisui would beat him otherwise.
Shishui try a q shot. Danzo teach him to respect a pimp. Gg shishui.