>>106694078It doesn’t. She’s just a really good fighter, who happens to also be deaf. You could even say that it really is a handicap, and that she’s a good fighter despite being deaf.
There may be some practical advantages to her deafness in a couple of the settings she may encounter in the field- for example: the dragon king apparently has a loud “deafening” roar that incapacitates human soldiers, and perhaps already being able to communicate nonverbally is advantageous in that situation.
But mostly that’s not the point of making her deaf. It seems to be strictly for representation, not because being deaf is some cool superpower or anything.