Gets unfair sometimes, to have a Twitch or Shaco on enemy side.
Pyke, Eve, and Rengar "tell you" when they go for ya, to react a bit (Eve with the heart that she needs to taunt you, Pyke with sharks, and Rengar with the screen colour and eyes).
There is nothing that tells ya that Shaco and Twitch are pretty much by your side.
Because assassins need counterplay, adcs do not. See: Vayne As for Shaco... Because he usually can't kill you with just q-e, I think.
Twitch, you can see when he's about to get you unless he ults. Shaco's like the worst jack in the box ever and just shoves a dagger up yer booty.
Pyke can do some really unfair stuff from stealth. Some fight-ending stuff.
Eve stealths constantly, so she needs the warning to offset.
Rengar's burst is ridiculous out of that bush. If you don't hear him coming, he can leap on you from a mile away and you'll be snared and ripped apart before you know what happened.
With both Twitch and Shaco, their stealth is pretty brief and they can't do anything too rapidly destructive off of it.
