Rengar's ult gives him too much potential pressure on the map

With assassins growing in popularity, Rengar is a problem that needs to be dealt with. Could his big oneshot combo's damage potential be nerfed? Of course, but that won't solve his true problem. It will just make him useless. The massive burst is what makes playing Rengar fun. As someone with over 100k Rengar mastery points, here is my analysis of his true issue:

If one team has a Rengar with at least half a brain, you can ward all you want, but the other team's squishies cannot leave their ally's sides without the threat of instant death, even if Rengar is on the opposite side of the map. He doesn't need to play the map correctly to gain this pressure. It only requires him to have the stats (items) capable of destroying a squishy. This is unhealthy for the game and can be fixed with one small change:

When Rengar uses his ultimate, it makes a global sound for all players to hear.