It can be seen as an extreme form of Edward's over - protectiveness. Since he is always so concerned about Bella's safety in the Twilight world, this could be a very drastic way of showing his reaction when she does something he deems risky.
One interesting aspect could be the exploration of the power dynamics between Edward and Bella in a different light. It might show a more assertive side of Edward that we don't see as much in the original series. However, this also has to be done carefully to stay true to the characters' essences.
Well, it's possible. Fanfics can take all kinds of unexpected turns. Some might envision Edward cheating with Seth for various reasons like character development or to create a more complex plot.
It changes the power dynamics. Instead of being the damsel in distress, Bella becomes a force to be reckoned with. For example, in many fanfictions, she can protect Edward instead of always being protected by him.
In fanfic, giantess growth can fit into the Harry Potter universe through magic gone awry. Magic in the Harry Potter world is powerful and often unpredictable. A misfired spell or a wrong ingredient in a potion could lead to a character growing into a giantess. It adds an element of chaos and novelty to the well - known world of Hogwarts.
Well, in many Twilight fanfics, if Edward leaves Bella, she often goes through a deep emotional turmoil. She might become very sad at first, feeling a sense of abandonment. She could also be angry, feeling betrayed by Edward. And she might become more withdrawn, isolating herself from her friends and family as she tries to deal with the pain of his departure.
Animagus in Naruto fanfiction can also be used to explore the characters' personalities more deeply. For instance, if a character is an animagus of a wolf, it could symbolize their loyalty, but also their wild and independent nature. This can be used to develop relationships between characters. A wolf - animagus might be drawn to others with similar animal - like qualities, or might clash with those who have opposing traits.
Often, it's portrayed with a great deal of passion. The spring scenery, like the blossoming trees and warm breeze, is described to enhance the mood.
Bella might go into a deep depression. She was so in love with Edward, and his death could shatter her world. She could become withdrawn and isolate herself from her friends and family.
Edward would likely be in a state of panic. He loves Bella deeply, so he'd probably do everything in his power to save her. He might search for a cure or a way to reverse whatever is causing her to die.
I'm not sure of an exact one off the top of my head. But if you browse through the Twilight section on fanfiction sites and filter by your criteria, you should be able to discover one that suits your interest. Different fanfics might offer different takes on this alternate storyline.