Malzahar was reworked so he couldn't win a 1v1 by just Flashing E W R you (while you instantly activate your QSS to beat his ass or at least escape from him.)
But Fiora can win every 1v1 because "She's duelist dummy, she's supposed to be unbeatable in a 1v1."
SirΤeemο1 votesmalhazar is not a duelist ..
Jinzo Torrance4 votesHis old kit made him one? "Never fight a Malz 1v1" "Malzahar is one of the strongest duelist if he has his ultimate" were common things to say about him in that regard.
Critmaster Garen1 voteswell, can fiora flash e, r, w on you and kill you?
no.
if fiora is too strong or not aside, these kits arent even close to comparable and malzahar needed changes for entirely different reasons.
you know damn well that between malzahar with 2 ranged point and click damage (+ ult supress) abilities being able to 100 - 0 his opponent, and fiora actually duelling her opponent while he can fight back and move around are worlds...
there is 
being really strong in a 1v1, and 
absolute 0 counterplay ranged point and click cc + burst.
is a duelist ...