Rengar needs to actually win something when he wins, "The Hunt is on" and a change Summoner Spells

So I was playing a game with a Rengar on my team, and a Kha Zix on the other team. At some point, "The Hunt is on" triggered. Rengar won the trophy, but since Rengar can no longer lose his stacks, and it takes nearly full stacks to trigger it anyway, Rengar doesn't actually gain anything from winning the side quest. Kha Zix gets his 4th evolution while Rengar gets only maxed stacks if he didn't already have it. With Rengar being no longer able to lose stacks, the quest is bound to be triggered if the two oppose each other.

The quickest thing I can think of off the top of my head would be that he always starts with one ferocity, or a chosen ability gives additional ferocity. Since he got the head of Kha Zix, he should evolve something just to rub it in his face (literally).

And while I'm at it, I also think Clairvoyance{{summoner:2}} should reduce the cool down of trinkets and Clarity should add some type of passive mana regen.

I think the 2nd part is just a good idea, but the first part definitely needs changed.