It seemed like you were arguing that there was sufficient synergy as is, which I don't agree with. If that's not the case, my apologies.
Regardless, there are lots of ways to go about it, either centered around changing the E or changing the W. For the E, two suggestions that I've seen are to either add a slow inside the circle, or to make the stun instantaneous on the part of the circle closest to veigar, and gradually move around until the full circle is closed off. This would limit his ability to stun people at long range, but give him some sort of immediate response to people close to him.
But the most interesting way to change him, imo, would be to add specific W effects when cast within the circle of the E, like greater AOE (this one is probably the best idea), greater damage, reduced delay, or some combination of these. You could even add a charge system (like with smite) with reduced damage for multiple hits on the same target.