Well, in fanfiction, anything can happen. Just because it says Harry is Uryu's brother doesn't necessarily mean it's going to be a traditional brother relationship. It could be a metaphorical brotherhood, or it could be a result of some crazy plot device like a cross - over between two different universes. So, it really varies from one fanfiction to another.
Well, a Nishimiya x Ishida fanfiction often explores the relationship between these two characters. It could be about their friendship deepening into something more, like a romantic relationship. The fanfiction might focus on their interactions, how they understand each other's feelings, and the development of their bond over time.
I'm pretty sure Ishida doesn't have a niece in the manga. Usually, such significant family relations would be clearly shown or at least hinted at, but there's been no indication of this.
One great ichigo x uryu fanfic is 'Bond of Souls'. It beautifully explores their relationship as they face a new and powerful enemy together. Their friendship is depicted in a very heartwarming way.
Ishida doesn't die. The manga follows a different trajectory for his character arc, emphasizing his personal development and relationships rather than a tragic end like death.
Neliel could be a great choice. She has a more gentle and kind nature compared to many other Arrancars. Her unique appearance and backstory would make for an interesting dynamic with Uryu. She could potentially teach Uryu about the different aspects of Arrancar existence that he may not be aware of.
One key element is their contrasting personalities. Ichigo is hot - headed and impulsive while Uryu is more calm and calculated. This creates an interesting dynamic in the fanfic as they often clash but also learn from each other.
A key element is often their contrasting personalities. Uryu is more reserved and methodical, while Ichigo is impulsive and passionate. Their interactions based on these differences create interesting dynamics.
In a fanfic, their relationship could also take a more romantic turn. Ishida, who has come a long way from his bullying days, might start to see Nishimiya in a new light. He could realize his true feelings for her as they spend more time together, perhaps helping each other with their personal growth and insecurities.