He is pretty bad, he himself can make plays but it is far too reliant on the team, and because of this he just feels useless more often than he should. He pretty much needs to be in one of his zones to do average damage, and there are no zones in the lanes.
His E is very lack-luster. its a slow projectile even before it passes through a target, so hitting multiple enemies is an uncommon occasion, and then you need to individually stun them.
So my suggestion is, just make his Q proc his E stun, landing a multi-champ E should feel rewarding as opposed to being a chore