A couple of thoughts on Fiora rework...
Well, I finally gave her a shot. I'm not a professional by any stretch, but here are some things I've noticed...
I like the concept of the kit, but the actual gameplay leaves something to be desired. First up, the passive is nice, but registering hits is crap. Also, why would you make a passive that is akin to Quinn's, but make it nigh impossible to land when the vital shows on the opposite side of the champ? Maybe also add a passive on one of her other abilities that allows her to not suffer unit collision? Or maybe make Q ALWAYS hit a vital? I dunno, seems non-synergistic.
W would be nice if it was instead an AoE, but with a much smaller range. I feel like the damage portion is wasted since it seems like 90% of the champs have some kind of speed buff or dash to avoid it. That, or you have to have amazing reflexes.
E I like. Wouldn't mind if it lasted three hits, last hit normal, but that's just splitting hairs.
R. R R R R... If the passive of no unit collision were a thing, it would make it easier to use. HOWEVER, Fiora now lacks the burst to really dispatch someone in 8 seconds, so hitting vitals is key, but since you have only one slow in your kit you often can't outpace your opponent. The other fantastic thing about her old R was the mitigation. I'm not saying she needs that level of invincibility again, but some kind of shield when she hits a vital or maybe a heal for the same amount of damage? I dunno. SOMETHING. Every game I've played with her, R has just been a beacon for the enemy team to focus me.
Overall, you have to build like a tank because building to do any appreciable damage comes at WAY too high a cost. Every other melee carry I can think of has a couple forms of mitigation, one of which is VERY strong. Hell, look at Yi. Probably not a great comparison, but he has an ability which makes him untargetable and one that makes him tough as nails at the cost of damage output. Just some things to think about.