Ao is very strong ninja you will want to make use of him.

Main Tobi *x
*x *x *x
Kakashi Ao *x

3
3
3
2
1 with Ninja Cat.

Just noticed you don't have Ninja Cat yet, meanwhile use one of the popular meta builds Tobi/Hinata/Kakashi, Tobi/GNW Neji/Kakashi, Tobi/GNW Kankuro/Hinata, they are all pretty strong so it's up to preference.