@Riot, The Kha'zix changes were in the right direction. But...

...He has too much trouble isolating a target.

300 was too small, 500 was too large, but he can't just have access to the small isolation range.

I was thinking:

What if evolving R also makes it so that his isolation range goes from 500 - 400? This would still make it require skill, and not have to wait for someone to separate too far from their team. Most of the time, they group and you can't take one. Only in early jungle levels can you actually use the isolation, unless someone doesn't have common sense.

(If I got the isolation range wrong, correct me; I basically want it to be -100 when you evolve ult.)