So i tried out Ekko...and well...I felt pretty BA just going in and out.
He is a rather cool champion, but i dont quite see the Op. If you dont build almost Pure AP he doesnt do the needed damage unless it is a prolonged battle and you are going AP bruiser. Sure he has burst, but if it doesnt do quite enough then the longer battle will usually be the end of him. I believe he is actually in a area in way of balanced due to the fact that other rather mobile champs and decent assassin will deal with him well. And tanks can just blow off most abilities unless they are low.
<----I believe he does. Along with a more reliable stun, Large AOE massive death. And a ult that follows them and stop any channles.