It's funny how people think Zhonya can stop Fizz Ult after it hit them xD
If you get hit by a Fizz ult and Zhonya, even if the ult missed there is still a dot that procs the passive. Soo Fizz only need to WQ and he will still instant kill you. 100% Ap ratio after 2 sec on W is enough + Lich Bane.
I had a game where Annie bought Zhonya thinking it would be enough to survive from fizz. Little did she knows that fizz has bigger ratio than before.