I don't want to see Rengar reverted

I'd just like to say, I didn't hate old Rengar, I don't like new Rengar, and I don't play the champ. Regardless of that, I don't feel like reverting him would be a good idea. Should Rengar be changed some more? Definitely. However, I feel that reverting him will only set him back to the problems he had before. With that in mind, here are some suggestions for future changes.

Rework his charge system: Currently Rengar has a charge system, filled by casting abilities/jumping from bushes, granting him a set of abilities, that operate on a separate CD from his basic abilities. Which, in a day and age where Assassins are supposed to have delayed burst, is a bit of a problem. Rengar can currently Q for damage, then empowered Q immediately after, provided he has the stacks, for even more damage. As a change, how about making his empowered abilities CD scale with his normal abilities CD? Say, you use your Q to max your stacks, and then instead of being able to immediately use an empowered Q, you have to wait a percentage of your Q's CD. For example, say its 60% of the CD. Instead of being an instant empowered Q, you have to wait 2.4s to use your Q, providing that it was your Q that procs the final Ferocity stack. Same with your other abilities. You can't empowered W immediately, if it was your normal W that was the final Ferocity stack.

Give him better in-combat mobility: Unlike pretty much every other Assassin, Rengar lacks a basic ability movement spell, which keeps his play-style as more of a Diver, than an Assassin. Perhaps adding a short leap to his W, would increase his viability as an Assassin. For example, something like this:

Battle Roar:

Passive: Rengar stores 50% of the damage he's taken in the last 1.5 seconds as Grey Health (75% versus monsters). Active: Rengar lets out a battle roar, dealing magic damage to nearby enemies and healing Rengar for his Grey Health. After the damage is dealt, Rengar leaps forward 500 units, approx 70% of leap range. When empowered, this leap is increased to 725 units, full leap range.

Just a thought.