Rengar ultimate is a joke
2 seconds wait time to get into stealth, alerting enemies from half of a map as soon as pressing R, camouflaged.
Camouflage is great tho, he can't go through your whole team and kill your carry, but to actualy do some positioning and thinking twice before ulting.
What I don't like is the radius that is really huge and it makes it worse as the game goes longer. Split pushers are also safer a lot, 2 seconds before you get into stealth alerting them as soon as pressing R from 4000 radius, giving them space to even come to the safe point and not getting punished by split pushing. In my opinion, he would be in a much greater spot if it does not scale up alert range by ranking up ultimate, so keeping it 2000 radius at all ranks would make him much better.