Riot don't nerf rengar

Rengar being picked was more of a "Ehh... We're probably going to lose against TSM anyways, might as well pick something that will catch them off guard by being something off-meta."

Rengar as he's meant to be built and played excels in the deletion of single, isolated targets, which is why he's pretty strong in Solo Q especially in the hands of Rengar one tricks, but not played much in Pro play unless it's a pocket pick or a picked-to-catch-em-off-guard pick

lol there's a ssw rengar skin for a reason, he's unbeatable in the right hands.

nerf wouldn't hurt him, even though he's mysteriously underplayed.

He has plenty of counterplay already

There is counterplay to him, xD kinda. Use or be quick AF Use or

I was once against a fed rengar lategame with Sivir, he jumped on me, and right in the air I Attacked him once plus W quickly for a double attack, the two attacks were crits (100% crit chance), he died so quickly and he didn't even touch me, it was cute.

Rengar is just one of those poorly designed champions that still has an unhealthy playstyle pattern post-rework. Gapclose, CC and burst has always caused problems.