champion that can be played with mouse only

[rijn dael]

G600 / naga, and should be fine

I dunno how you would go with combo characters like katarina/leblanc where it is all about the speed of the combo, often combining items / summoners.

Teemo would be perfect though

[Vodkatwist]

I'm a clicker on wow (yeah, shame on me, even though I accomplished quite a lot in the past :P) and I ASSURE you you must bind those 6 spells+items

[cherb]

Probably none of them without a mouse with a bunch of extra buttons. This game wasn't intended to be played with just a mouse. All of the champions are designed around having all of their abilities bound to a key. It would be pretty awful to try and click the spells as you use them, you'd get outplayed every time. Even being really slow on a keyboard would be better than trying to individually click the spells.

[Deleted]

Indeed no champion is ment to be played with a mouse only, so you wouldn't stand a change against other players..
However a good champion I can think of for this would be Sion. (Especially when going Attack damage on him).
You can activate the ult or shield etc without having to interrupt the autoattacks so I think he fits that playstyle best.