[{quoted}](name=Neo Cyrus,realm=NA,application-id=3ErqAdtq,discussion-id=htEgXohj,comment-id=00000000,timestamp=2015-12-27T02:12:51.270+0000)
Okay, totally not biased Gold Rengar main.
To answer your question OP, it's because he's bullshit that lacks any true counterplay and always has been. Name one champion that can 100-0 an enemy carry while not fed FROM INVISIBILITY that's not bullshit? That's right, anything that can do that is BS and shouldn't exist.
The responses as how to "counter" him are absolute nonsense "position better", "buy pink wards", like that'll stop him from exploding you and running away faster than most people can respond. Might as well write "just win the game".
Rengar will get nerfed, especially considering an AD DFG is coming (yeah they're smoking a lot of crack), it's just a matter of when.
Well, he's kind of right about positioning better. I got to admit pink wards don't work if they're good Rengars, because they just speed in and jump on your ADC, but the positioning part is right. If your ADC is behind it all and blocked off, they can drop pink wards so you can see him before he jumps. Then again, there are usually multiple ways so we'll leave that part out. But if you have people protecting your ADC, Rengar will probably destroy them... but then die himself.
If all assassins were actually assassins like Rengar, then the odds would be balanced. They could go in, wreck face, and die. I mean, that's what they're supposed to do right? Take out one target and either live and be done, or die and be done. Either way they've taken out their carry and made it worth. If they get peeled off before they can burst a squishy af target, then they aren't an assassin, plain and simple. Almost no assassins are really assassins, unfortunately. We have Rengar, kind of Talon(when he gets at least moderately fed), Fizz kind of because he's untargettable during his troll poll so it makes up for the time because he'll still at least get the kill. But other assassins like Zed, Ekko, Kha'zix, etc., aren't really assassins. They take too long and can easily be interrupted from their assassination and made useless, which I find stupid. Others like Leblanc, and including Zed and Ekko if they're fed and can burst very fast, can easily get out of their assassination and not die, as well as have low cooldowns and can easily get back in safely. Rengar has low cooldowns, but can't get in safely, Kha'zix can with his E, but doesn't burst fast enough and requires isolation so if you're not stupid you'll have a bodyguard with your carry.
TL;DR: Assassins should be like Rengar, eliminating their target and then dying or at least not being able to get back in the fight without risk. Hence "assassin."