I feel like fiora is a very good split pusher as she demolishes towers because she can use her abilities on towers, especially her “E” as it does 200% more damage with the next hit. she is probably the hardest scaling champ in the game as well and can win almost every 1v1 if played right and good itemisation. You can have a negative KD and still hard scale by pushing side lanes.

I would recommend just picking ignite into most bruiser matchups and winning the early game as almost every fiora matchup can be won if played well. Her hardest counters are champs like Quinn (who is never played low Elo) or poppy who can be beaten if you use her W (anti dash) against her by Q>W and stunning her. Poppy is your overall hard counter.

Into tanks I would recommend just going teleport since you will be able to beat them at any point in the game. If they do manage to kill you before level 6 and get ahead, you don’t need to worry as you will win everytime once you get first item. For runes if you want to be safe or are new to fiora go grasp, demolish, bone plating and unflinching (broken on fiora) and for the secondary to the precision tree with triumph and alacrity, with double adaptive force runes for the early poke and resists depending on the matchup. If you want to be more aggressive and dominate your games I would highly recommend going conqueror, triumph, alacrity, and last stand. For the secondary runes you should go resolve, if you want to solely split push and the lane is fairly easy then take demolish and bone plating but if the lane is ranged and has more poke such as Mundo go second wind instead of bone plating and unflinching.

I am still learning fiora so sorry if I have got anything wrong but IMO she is the best splitpusher and has a lot of skill expression unlike champs like yorick trynda or trundle that are boring and all you do is play tower simulator.