Here's a theory on why Fiora's bangs/blocked eye is important.
#Please keep in mind that this is basically head canon and merely theory.
So one of the things that happened with the Fiora VU is people were upset with her hairstyle change. Her hair was iconic, her bangs were key, the one hidden eye was core to her character. I found that odd, as I kept seeing people say that a blocked eye for a fencer is a death sentence and poorly planned. That you need both eyes to effectively fence. Why did people respond so strongly to it?
It hit me then: Fiora has her bangs like that as a handicap to you.
Fiora, as a character, is both powerful and arrogant. She relishes facing a worthy opponent and is more than happy to demonstrate how she is the grand duelist. In much a way that a martial artist would tie one hand behind his back or only fight with his legs to make it a fair fight for a weaker opponent, Fiora does the same thing. Except in fencing, she's generally using one hand now that her parrying dagger is gone. So how does Fiora handicap herself in a way that makes sense?
Simple. She reduces her field of vision and fights you with what is essentially one eye closed. THAT is why her bangs are important. She's not afraid to face you with her vision obscured, she's not scared of having her hair blocking her eyesight. She's going to fight you with an impractical hairstyle because she can STILL kick your ass and look damn fine doing it.