And stays stacked too long after you do stack it.
I'm convinced this is one of the things that makes him overbearing. He can get 3 stacks with a rapid auto-Q-atuo, then do 30% of your hp with one ability. Then after he spits you out, you _still_have full stacks on you, and you will until his Q is back up at which point he can stun you.
Keep in mind the stacks stay on you for _seven seconds_. This isnt like a Velkoz passive that gives you a bit of extra damage, when TK gets three stacks, he can cc you for 6 seconds, and deal about a third to half of your hp bar, all with zero offensive items.
Given how much power TK has when he does get stacks on you, he really should have to actually work harder to get them.
I'd say halve the stack decay rate, and have his abilities actually consume stacks when he procs them, so when he eats you and spits you out, you dont already have 3 stacks on you again. That way he cant perma cc you, and chunk your health bar all while being litterally impossible to kill.