In 'growling and more growling twilight fanfiction', the repeated use of 'growling' might also be related to the unique characteristics of the Twilight universe. Vampires and werewolves are central to the story, and growling could be a way to emphasize their primal instincts. It could be a part of the way they communicate or a sign of their power.
If the fanfiction focuses on the growling in relation to the unique species in Twilight, like vampires and werewolves, it can attract fans of the original series. They already love the idea of these supernatural beings, and the added element of growling can enhance their experience. It gives a new layer to the familiar characters and their relationships.
Once, I was in a really quiet library. My stomach suddenly started growling super loudly. It was like a mini thunderstorm. Everyone around me looked up, and I turned bright red with embarrassment.
Nezuko is initially 12 years old in the manga. As the story unfolds, her age doesn't change significantly in a traditional sense, but her character development is quite remarkable.