Fiora is one of the most unique champs in the game. She's has a very great ult for team fighting, and even more so for 1 versus 1.
I personally don't think she's like Yi or any carry. I play her more like a Riven if there is any champion I should compare her to. Her team fight potential is beyond recognition. Being able to shred carries, and jump from person to person in team fights. She's superb.
Pros / Cons
Lots of Damage
Good team fight mobility
Very strong top lane
Decent bottom lane
Very vulnerable to CC
No built in escapes
There are a few different things you can do for runes. I haven't been able to experience at all, due to me not having my main account.
Right now I've just ran flat ad, which makes last hitting very easy in the early laning phase, also by maxing W, makes her 1 to 2 auto attack hurt a lot more.
Other viable runes, Armor pen marks, and Armor pen quints,
I like taking Flash and Ignite, if I'm playing top/bottom.
Viable top lane summoners, Ghost, Teleport, Exhaust.
Jungling I like Smite and Flash, but you could replace Flash with Ghost.
I think Flash is a pretty necessary summoners, since she doesn't have any sort of built in escape.
I prefer maxing out W for the cdr on your Riposte, and the extra damage is great. I don't find her Steroid very reliable, because if you get cc'd shortly and don't land your auto attack for the move speed, it's pretty useless. Being able to riposte as often as you can with level 9, and brut, makes for better trading, and better Ult damage. I like to take her Q at level 1, for the level 1 trades, jump in land a couple auto attacks, and when they run Q to them again. Can be used to poke them and dash back to minions making an even safer trade.
Fiora is fairly dependent on farm, as any other champ. The most important thing in this game, is to manage harrassing, and trading with farming. Focus on farming, if you create an early game edge, you won't have to worry about being contested. There are so many games, where I either pull a kill by level 4, or force them to back, and I get the small level advantage and item advantage. The lane really snowballs after small things like that.
You really need the early Doran Blades for the health, the damage is useful. Early game on any champion is all about health effectiveness. You need health to trade, you could have a Pick Axe and have more damage, but 200 less health to trade. Instead of coming out of a trade with 500 health, you'd come out with 300. Making your play much more passive.
I always like to get a QSS in about every game as you can see, Fiora is very vulnerable to CC. If she gets caught in a stun in a team fight, it's not a good sign. Plus QSS cleanses that Exhaust, or Blinding Dart Teemo hits you with. It will completely ruin your ults damage and the life steal.
It depends on the teams, but Guardian's Angel is a really good item for Fiora. It allows you to get in on a team fight, and be aggressive on the carries. If you're building right, and you're farmed. You should be their target, giving your team the chance to target carries. Once you're back alive, if you didn't ult, you can ult and get your health up a significant amount.
If you start your game with an early wriggles, it helps a lot with dragon/baron/grabbing that red buff while you're in top lane. But when late game comes, always make sure to trade your Wriggles out for a Blood Thirster.
I personally don't think Phantom Dancer is a necessary item on Fiora, I haven't really tried it out. Just for the fact I don't think she needs it. Her E gives her so much attack speed and move speed, I think you end up doing more damage either getting a Triforce or just stacking Blood Thirsters.
Fiora is a strong bully in lane, Fiora's early game is where her strength is. Once you create an edge in your lane you need to hold it. There are a few games, where I can draw first blood before level 4. Having all her abilities at level 3 makes her trades significant.
When dashing into an opponent, I like to pop my E, just before I Q, that way I get the movement speed increase from E, just by Q'ing it allows me to stick to my enemy, and if they attempt to trade, you W, and chase. Fiora has a very strong trade early game.
After you hit level 6, if you can harass your lane down to about 300 hp, it's almost guaranteed you can dive and get the kill. Q into them after hitting E, attack a few, ignite, and pop your ult. There is absolutely no way they can surive. Legitimately, no way. If you're just level 6, even if they have a Soraka on their team, she's only going to be level 4. No ult, if you do get ganked, they can't target you because of your ult. There have been many times, where I have done this and the person I dive panic's and either flashes away from the tower, or uses an ult just out of not being sure what to do.
The main gold as Fiora is to create an early game edge, and hold it the entire game. If you play it right, you can freeze your lane near your tower, and sit right in the middle of the creeps. If he comes to farm you jump onto him forcing him back away, or to base. Neglecting farm from your lane is so huge. It's all about doing each and everything you can to keep them down while building yourself up.
The first ranked game was my first game with her. I did it in ranked, because I knew I would be able to pick her, I duo que'd with my friend who was lower ELO so I could be top, and get first pick. After that I did some pubbing, none of this is spliced this was my 10 game match History. Right now I'm 14/0. I am yet to lose a game as Fiora. You can actually see, there are 2 games, from the top list that are on the bottom list proving I didn't photoshop this o:
When playing Fiora, your gold in every team fight is to take out the carries, her DPS is so high, and if you play it right, get your health a little low you can pop your ult, shredding carries and getting a significant amount of health back. If the carries are playing back very far, just do your best to stay with your team, focus appropriately. Regardless of how they are, it should be your goal to dive to them and kill them if possible, if not killing them, they might blow their flash, forcing them out of the fight is just as effective as killing them.
Her jungling route is just the same as every jungler, Wolves > Blue > Wraith's > Golems/Red > Red/Golems.
This is only the first guide I've ever made in my life. But, Fiora is an extremely strong and viable champ in almost every role. Top/bottom/jungling.