So... The ONLY reason you want to rework Professor Eyeball is because he lacks a gimmic?
The problem is just: where do you want to add that gimmic? Q and W are unique to him, E is kind of debateable but works well with W and his ult is pretty much what makes him our beloved "FIRING MA LAZOR!"- void-noodle.
That leaves one thing in his kit that might be replaced: his passive. As it is now it's a pure stack-to-damage-mechanic to either gate his damage and reward hitting combos.
Ok, but you are still desperate for a gimmic? Well, ok let me think... It has to be something with his theme too. But what mechanic works with an GIANT ELDRICH EYEBALL?
New passive: Chanelled observation. Vel'Koz has a higher vision range, but only towards the direction he is looking to. The vision to the sides is decreased while he has almost no vision to what's behind him. Up to a certain range he has true sight, because the fabulous eyeball is not impressed by your pesky little invisibility tricks.
New Passive, Part 2: Focussed Analysis. Repedeatly dealing damage to the same target in your vision cone increases that damage, depending on how much you hit them. (Pretty much his old passive but without stacks. "Hit them much for more damage")
Ideally the maximal vision-cone range should correlate with the maximal range of his ultimate.
You want a gimmic? Here ya go. Just don't touch the active parts in his kit too much, they are pretty much fine as they are now.
