If he's not within arm's reach, you can combine a QSS usage with a defensive Flash or some other escape mechanism to get away from him before you die. In common situations, you can just wait in the back and he'll ult your team - you can just kill him then.
Who is good against Fiddlesticks?
Fiddlesticks Counter Pick
The strongest counter would be Ivern, a hard to play champion who currently has a Win Rate of 51.74% (Good) and Play Rate of 1.72% (High). League of Legends most often picked champions vs Fiddlesticks, this is often heavily influenced by champion popularity.
Is Fiddlesticks a hard champion?
Is Fiddlesticks hard to play? Fiddlesticks is a fairly easy champion to get a grasp on, but is hard to master. Fiddlesticks has always been a champion that relies on hitting a good Crowstorm ultimate and that is still the case after his rework.