Sick of rengar being able to cast every ability faster than any other champion
He can cast his entire kit in less than 1 second WHILE LEAPING. Sound familiar? Prenerf 
He can cast his entire kit in less than 1 second WHILE LEAPING. Sound familiar? Prenerf 
I was thinking 
Rengars leap is a modified auto, Kha'zix leap is an actual ability. I do think Rengar needs a cast time on his E and W though so they cant be simultaneously cast for instant kills.
Also K6's bigger problem was letting his passive work on his W, the probably could revert the cant cast W while in midair and he would simply be into a reasonably strong state, but not rengar tier (It basically would just let him instantly clear the minion wave when ganking rather than having his laner blow a spell to help do it or telegraphing the gank a little bit)
Talon,Diana and probably more
?
Oh wait, it takes her 2 seconds to use all of her 6 abilities. While also hitting you with empowered basic attacks. Balanced as fuck.
Except Kha at his prime was far more broken than Rengar has ever been.
The thing is so can
and its a reason I hate her. She is a burst ADC with DPS and range and a reset and self peel out the ass. Rengar I only dislike when people feed him so he is actually useful. Because pre-6 he tends to have very little presence in the game. If you nerf armor pen stacking (like I have said for a million times) you put a lot of people who causes problems in line.
But no I'm wrong according to the community. Because the counter to stacking armor pen is HP which is less effective overall than armor in low amounts. Building 15 armor tends to do more for you than 150 hp against AD due to hp regen and healing. HP is just a pool that they have to get through. Remove the ability to stack armor pen effectively and this game would be in a much better state.
Him casting his abilities fast isnt what bothers you, its that they all go off instantly on landing that is annoying.
There are other champs that can pop off full combos in less than a second (mostly assassins), but they dont deliver their damage as swiftly as Ol' Rengo dose, or basically at the end of his leap.
While en route to enemy ADC durring ult, hit Q to ready Savagery, then 1 key for
to get extra move speed, and in case u need another auto, then mid leap hit E for Bola, then W for Roar, finally hit 2 key for
crescent active, your all set just keep hammering Q for the followup Savagery and watch them pop like a water-balloon.
So really the only things he cast "fast" are his E then W mid air. His ult was a while ago and his Q was when he got in sight of you. So its not all of his abilities are being cast faster than any other champion. Infact almost every other assassin uses their skills in a much tighter combo often finishing off with the ult. Rengar just initiates with his, then "cast fast" E+W.
So again, him casting fast isnt what bothers you, kind of a fail thread. Cause what bothers you is his burst, not the swiftness of his casting.
I like Rengar, but after playing him a bit to learn how to counter him better... there isnt really a counter to him. I read up on how to use him and was carrying games 4 matches in. His burst is obscene, he has no resource to manage really (as far as gating him from using abilities), he gets pretty massive benefits from the current mysteries.
After playing him a bit, yeah hes honestly broken. Broken in that the manner in which he contributes his kit to a match inst healthy, and the counter-play is really only teamwork, and since defensive teamwork can be countered with offensive teamwork, then were back to no counter-play vs his insta-gib kit. Yes you can ward.. but you do that vs any jungler champ. Yes you can avoid going off solo, but you do that vs any comp with an assassin that picks of solo pushers.
Rengar isnt stupidly overpowered, he can be a non threat like any underfed assassin. Still when he isnt, he seems to just offer that consistent threat of immediate ADC removal with a strong initiation, that almost no other assassin can manage. How many other assassins have the team saying, "Oh, X champ used their ult, lets go in an capitalize on this!" When Rengo ults, the team follows cause they know this is about to be a 5v4 in the same way a lucky Blitz pull turns the fight around instantly.
Rengar needs some kind of rework, the basic fact is that some champs have oppressive kits that just dont belong in the game. Any "nerfs" to him will just dumpster him, and have him going unpicked till hes buffed again. Left as he is, he is either useless or a 0.1 second squishy poping machine. Neither is good.