As much as I love ChoGath this is insane
Cho'Gath
[Looks like a few Air Client changes - enemy champion kills with R give 2 stacks AND if he kills an enemy unit with feast when he is already at max stacks feast will heal him instead - double heal for enemy champion.]
"Ravenously feed on an enemy unit, dealing true damage. If the enemy unit is killed by Feast, Cho'Gath grows in size and gains 90/120/150 maximum Health (maximum 6 stacks). Cho'Gath loses half of his stacks on death.
Minions and Monsters: Deals 1000 (+0.7) true damage. If Feast kills the target, 50% of its cooldown and mana cost are refunded and Cho'Gath gains one stack of Feast.
Enemy Champions: Deals 300/475/650 (+0.7) true damage. If Feast kills the target, Cho'Gath gains two stacks of Feast.
If Cho'Gath has reached 6 stacks, killing an enemy unit with Feast will simply heal him instead. The heal is doubled when Feast kills an enemy Champion."
He's already an extremely strong champion. This is far from needed.