Aside from having cat-like reflexes and the entire map pink warded...

...how do you not get deleted by Rengar (pun intended in the title) when you're not a tank?

Played a game as Vel'Koz yesterday. Was the only person on my team to not lose lane, so I would gank top and bot to help push turrets, and eventually we were up in dragons and turrets (and even gold, according to the post-game statistics). However, the enemy's top laner was Rengar who got quite a few kills off of our top early on, and I was the most fed person on our team- my teammates weren't doing terrible in terms of kda and cs, but level-wise, I was the only person on my team who was on par with the enemy, so if I died, teamfights were pretty much impossible to win.

At this point in the game, Rengar had enough items so that, even in teamfights, all he had to do was jump on me and I would die- even if I was able to do damage to him, he had enough health that I couldn't kill him faster than he could kill me. It got to the point where if I tried to ward a bush, Rengar would be there waiting to pounce on me. I was warding Baron at one point, and Rengar jumped from a bush and killed me. My team couldn't fight without me, so the enemy team got a free Baron, and all hope of coming back from a poor early game was gone. We eventually surrendered, but might as well have done so once my dumb ass got caught. Had I been smart enough to not get caught ever, we still would've had a chance, but that's hard to do even for people who are actually relatively good at this game.

So, what do you do when there is a Rengar on the enemy team and you're a fed squishy? Because at the moment, I feel like the answer is "have perfect reflexes and never go near a bush ever," especially since he can jump on you and kill you even when you're grouped up with the rest of your team- unless he's locked down by hard cc instantly, he's going to kill you.