What nerf should skarner get?

In my opinion his damage needs to get toned down just by a bit. That's all he really needs. His tank is enough to dish out the pain and everything else is fine. However. That freaking vision he can get needs to be different. Why? Because activating it seems Just a little bit pointless.

I think his vision should activate every time he gets within the circle, but decays when he leaves it. What do you guys think?