Can we honestly get this reworked? It is easily one of the best passives in the game. He is a rock in lane phase, you cannot get him out of lane. His passive just works so well with his kit.
Low on life? Q casters and Feral Scream the whole wave, you just got over 200 health back and you are only level 6. Repeat next wave.

Enemy tower diving you? Q, Silence, Feast to gain an instant 90 health from your ult passive and another 40 from your passive.

Yes, i am mad. As a top player i have to deal with Chos every game and it is honestly just enraging to face him.

You cant do defend yourself, one Q and you are at least half from a combo.
You cant fight him, he'll just use his passive and regen back to full.
The only way to beat a cho is to have your jungler camp him. This should not be the only way to kill him. Rework his passive.
EDIT: Since a ton of people are commenting on the match up, i posted this after the loss when i was very angry. I was constantly ganked by their Skarner, and the Cho'Gath would spam rupture when he has mana regen runes and a dorans ring, I tried to get my jungler to gank but he actually fed him a kill and the lane got out of control.

Now, as a serious note, the only thing i would say is take some off the health and make it restore more mana. Right now the health restore just is annoyingly high and the mana restore is annoyingly low.