I played adc today. They had a Rengar. I should be reported for AFK.
Question: Why does Sion need a global notification and not Rengar? Another Question: Does Rengar really need 45% movement speed when exiting stealth? Youmuu's is already a core item (Unless you're using NB3 build).
Rengar doesn't need a global notification because you can stop his engage with well-timed CC and GOOD vision. Also, you're not considering the psychological effect of a global notification: every lane gets really scared whenever that notification goes off whereas, the current rengar ult only alerts the targets within its range. On top of that, players can inform their allies of rengar's current location and use that knowledge to make better rotations/decisions around other parts of the map.
Sion , on the other hand, can't be stopped during his ult.
Furthermore, assuming youmuu's is a core build on rengar to justify removing the extra movement speed he gets is an awful idea. Build diversity is something to respect.
I agree with everything you said and had this idea about it: http://boards.na.leagueoflegends.com/en/c/gameplay-balance/JicBjl9z-lets-make-rengars-ult-healthier-and-more-interesting
The only one who can outplay rengar is 
, considering that Rengar isn't extremely fed
Rengar is absolutely cancer and common balance rules don't apply to him.
Rengar: Gank bot, kill ADC under turret, crap on the support, disappear back into jungle. Repeat for profit.
He isn't broken. It's just he's the most anti-carry champion in the game to the point that all he needs to get ahead is to camp bot lane. It's annoying how much control he has over the game play just for that. Even if you farm safe under turret. Rengar and friends will just 3-man dive you and laugh at the support's pitiful attempts to peel.
Whats with the Rengar threads popping up lately. When I got Rengar I sucked with him. Now I've been using the crit build and I can steamroll any non-tank champions. Rengar is cheese samething with Tahm Kench. I doubt that Riot will gut these two champions but they did ruin my Kha with these item and mastery changes ;-;
Ya know, out of all the assasins I'd say Rengar is actually kinda "meh". At least Kha Zix can instastealth with no warning symbol revealing he's nearby, Zed and Leblanc can "Flash" into you and gib you then flash out and still have flash up to escape. Fizz is, well he's Fizz.
I just don't get why Rengar gets all this hate when so many assasins do his job better it seems.
