Her relationships with her human friends will surely be affected. They might be scared of her at first, or she might be afraid of hurting them. So she may start to distance herself from them.
She may also find herself in a strange relationship with the vampire who turned her. This vampire could be either a mentor or a manipulator. If it's a mentor, they could help her adjust to the vampire life. But if it's a manipulator, they might use her for their own purposes, like using her to get to her human friends. In any case, all of her relationships will be in a state of upheaval and transformation.
Her relationships with humans would likely become strained. Humans might be afraid of her now that she's a vampire. Her romantic relationships could also change. If she had a human lover, they might have to reevaluate their relationship. And her friendships with other vampires could shift too, depending on how they view her new status as a turned vampire.
Her relationship with Inuyasha would be greatly affected. He might be initially shocked and even a bit distrustful since he has had his own issues with demons in the past. But over time, he could come to accept her new form and help her control her new powers.
Well, she might struggle with her newfound vampire nature. Maybe she has a hard time controlling her thirst for blood and accidentally attacks someone she cares about.
His relationships would change drastically. His work colleagues, for example, would notice his different behavior. He might start to work at night and avoid daylight. His relationships with other vampires could also be complex. He could form alliances with some vampires who are more sympathetic to his situation, while others might see him as an outsider. In his social circle, he would become a mystery to those who knew him before, and he would have to find new ways to interact with people.
His relationship with Sasuke would likely be affected. Sasuke might initially be suspicious of Naruto's new form, thinking it could be a trick by an enemy. But as time goes on, they could find new ways to work together. Naruto's new Kitsune powers could complement Sasuke's skills. For example, Naruto could use his enhanced speed as a Kitsune to keep up with Sasuke in combat.
His relationship with Tails would be strained. Tails would be confused and a bit scared at first. Sonic would have to hide his new vampiric urges from Tails, which would create distance between them. With Knuckles, there might be more of a distrust as Knuckles is very protective of their world. Knuckles might see Sonic as a threat now that he's a vampire.
His relationship with his friends would likely become more strained. They might be afraid of him or he might be afraid of hurting them. For example, his best friend Scott, who is also involved in the supernatural world, might be worried about Stiles losing his humanity.
His relationship with Ron would definitely change. Ron might be a bit more hesitant around her at first, not really knowing how to act. But as time goes on, they could develop a deeper, more platonic bond. It would be like Ron having a sister all of a sudden.
Well, with Dipper becoming a girl in the fanfiction, his relationship with Mabel would have a new dynamic. Mabel would be all about embracing Dipper's new form. She'd be planning slumber parties and trying to give Dipper a new 'girly' identity. As for Wendy, Dipper might find himself more in tune with Wendy's interests on an emotional level now that he's a girl. Wendy might be more open to sharing her feelings with Dipper - girl. His relationship with the townspeople could also change. Some might be more accepting, while others might be a bit more judgmental. And his relationship with the supernatural elements in Gravity Falls could be different too. Maybe some entities are more attracted to his new form, while others are repelled, which would lead to a whole host of new adventures and challenges in their relationships.
Well, Percy's relationships would be in upheaval. In the case of his friends, the dynamics would shift. His male friends might have to reevaluate how they interact with him. For example, they might be more cautious about physical contact or their language. His female friends could either embrace her new form and become closer, seeing her as one of them now, or they could be jealous if Percy in his new female form gets more attention. And in terms of romantic relationships, if Percy was interested in girls before, he might now find himself attracted to boys, which would completely change the nature of his love life.