Fiora bugs
I've noticed 2 bugs with Fiora, the first is just an audio thing but the second affects gameplay and can be quite frustrating.
I've played two games as Fiora where there was a Yasuo on the enemy team. Whenever Fiora hits an enemy with her Q (irrelevant of where Fiora is on the map), the sound effect that is supposed to be played is replaced by the sound effect of a Yasuo Q hitting a target.
The second bug is a bit more game changing. When there are 2 Fioras in the same game, her passive seems to break; sometimes on hitting a vital on an enemy, a new vital will not appear until about 15 seconds later on the same enemy (this is also independant of where the Fioras are on the map).