Kha'Zix consumes and evolves, right?

So why is he entirely based on level up?

What if we made it so that he gains 3% of all of the enemy champion's stats on kill, and 1.5% on assist. Might be somewhat strong, but could be changed around to make it work.

After all, Kha'Zix consumes and adapts. By doing this, he gains more damage if he kills someone with a lot of damage, he gains if he kills a tank, and he gains bonus healing and passive damage if he kills a mage.

I have always felt like Kha'zix thematically needs to get stronger from fallen foes. And I feel like this might be a good way to do it. This way, he doesn't really have control over what stats he gains. So it wouldn't be utterly ridiculous.

Edit: I have a better idea. What if, instead of gaining a small percentage, he instead gains something like 6-8% of all stats. Instead of automatically gaining said stats, the enemy's corpse becomes interactable for the next 5-15 seconds (based on level or ult level). Kha'zix can interact with each corpse once, channeling for 1-0.5 seconds to gain the stats.

EDIT 2: Make it so he gains a glow similar to that of an elixir, getting more and more intense as he gains more stats.