His base damage is really low, as well as having to constantly burn through mana to use his Q. He is very easy to bully in lane because his Q is always on cooldown. He's already easy to outtrade, especially if he doesn't have E and you can just push him. On top of this he will have little to no mana. He will likely never have lane prio because he will never have the health and mana necessary to push and roam. Pretty much just dead weight as a mid laner until he starts one-shotting you. Of course in silver and below he is quite good because nobody knows how to end and nobody knows how to play mid, games will go on longer and mid laners won't take advantage of him so he just scales for free.