The best picks globally to counter 피오라 include 제리, 케이틀린, and 칼리스타. These champs are all good at countering 피오라 with high win rates over 56%. Even if these 피오라 counter picks are not picked in the same position as you, it's not a good idea to take her into these matchups. They will likely win against 피오라.
Conversely, if the other team choses either 스카너 or 케넨, you should seriously consider choosing her, as she easily wins against these selections with win rates over 53% against each ofthem.