Cool idea for Veigar

With last patch we were announced if Veigar had some trouble he will changed a little bit to improve him. I have a cool idea that would make his E feel more like Veigar's torture room. What if after the 0.75 delay that was added, when the walls appear, if an enemy is caught inside the ring he would lose vision of the map, just like with Graves' smoke screen?

I think it would be a fair change, right now if you don't touch the walls, you can be inside the ring somehow relaxing. It would be more of a torture if you couldn't see what's going on outside the wall, and that would be pretty scary. Veigar would love that for sure.

Sorry for the bad English