I've tried a number of solutions on how to counter her.
* Q - too slow and easy to dodge
* W - she jumps over them.
* R - barely slow her at all.
* 600 ms with chilling smite
* Q - When you grab she's soon out of range again.
Being the most obvious, beyond that a fully fed Rengar will do the job.
Only hard cc seems to work, but most of that has now been changed to skillshots which she pretty much counters through mobility, so how about giving her some other form of counterplay, such as:
* Silence negating the jump.
* Hard cc negating her next jump.
* Windup mechanism giving her periods of vulnerability when out of combat for extended periods of time.
The current project is to lower the benefit she receives from buying Attack Speed by fiddling with the attack animation at high attack speeds.