Your Tanky and your dealing tons of damage.
Tiamat: This deals true damage, use your ulti on a team bunched up a together a penta kill is possible.
This is just my personal build for Fiora, This build allows you to be tanky and be able to do tons of damage. Since Fiora is very easy to kill Frozen Mallet is a good choice giving her health and is able to chase down foes cause of the passive.
Always use your E when going into a fight, atk speed is her probably her best ability, make sure to activate W as your about to attack this way you'll parry the hit and that can be very useful.
Lung to reach enemies from far away straight away activate another Lung, than activate your attack speed, than as soon as possible activate Riposte.
This process is for quick excecution, also since Fiora's ultimate has a short cooldown don't be afraid to use it, and yes you can dive turrets with it. Also with the Tiamats it will deal more damage plus TRUE DAMAGE. So use it in team fights, to get the splash.
I do not recommend buying atk speed for Fiora, since she has her E, so Berserker Greaves can act as your atk speed, also I did not choose Black Clever cause of its ATK SPEED but cause of its passive to lower and enemies armor by 30%.
Thank you for reading my quick and simple guide.NOW GO GET YOURSELF A PENTA-KILL!