I was assuming it was around midgame, which is my fault I suppose. In endgame a carry is supposed to melt a tank, Fiora is (or was) a melee carry
The main problem i have with her is that after those three items she doesnt need anymore damage, she can just go off tank. Bursting her is very hard if she gets some defense and uses her w well and fighting her in a sustained fight will melt you. It doesnt help that if she ults someone and they die her entire team gets healed to full health midway through a fight.
The vitals will never spawn in the same spot if she pops one, she'd need to be running circles around you to pop more. If you manage to have a vital pointed to a wall she can't ever hit it (if you hug the wall). Fiora is countered by proper positioning.
50% movespeed buff on hitting a vital or till ult runs out if she has you ulted + 2 sec cd on her q with 40% cdr (Which is possible if you go scaling cd blues, spirit visage and cdr boots.) Unless you're playing someone like riven or yasuo out positioning her is near impossible.
Play against her like you'd play against a master yi, cc & burst kill her (yes, she can parry, but it only lasts for .75sec and she is stunned while parrying). The advantage you have against fiora is that you know exactly where she wants to be (your vitals.)
Most cc has travel time, unless you're playing annie and can instant stun you she can parry it, combined with the fact that if she's can just wait for a fight to start instead of diving head first into your team 1v5 and still be just as effective at bursting tanks. Also her vitals arent as much of a positioning weakness as say dravens axe's. If draven drops an axe he's got no damage, if he gets cc'd while catching an axe he's dead. If fiora doesn't proc passive she still has her ult for at least one free proc and deals respectable damage with her q and guaranteed e crit, if someone tries to cc her while she's going for a proc she can parry and now her target is stunned and she can proc her passive easy as pie.
Now I'm not saying you can't dislike her, I dislike yasuo, zed and katarine whether they're op or not.
Fair enough, i dont think she's op i just think her power should be shifted away from her passive. 100% max hp true damage is ridiculous no matter how you phrase it.
Personally i dont mind zed or katarina, they both have their counters, counterplay, and counterbuilds. Yasuo's windwall gives me cancer if im playing anyone with projectiles. My pet hates are fizz and rengar.