Fiora Ideas

First off, make Fiora's hit detection on her passive better and more responsive for the vitals be a good start.

The changes (buffs) I would do for now is lower Fiora's W cooldown to something like 16/14.5/13/11.5/10 seconds for it can be used for waveclear maybe even make it deal increased damage to minions.

Another one is make her E's slow duration slightly longer.

I would look towards something like this if you would do any buffs on Fiora, stay away from doing damage buffs otherwise you may end up with old Fiora status which is not good for the game (probably not because the kit may be changed well enough that the bad gameplay is removed).