Increase Rengar's ! Warning Range
The whole point of the ! was to give people warning when a Rengar was in the area, but pretty much after he gets 6 trophies, it never shows before he is mid jump, this means the only warning you get it when he is jumping onto you, which is no different than before the ! was added, Riot needs to increase the range that it will warn you so that he can't just inst jump on you with no warning, like before.
Or the ! is bugged and isn't showing correctly when he is within range.