Another reaction could be that Percy is worried about Sally getting into trouble because of him. He might try to convince her to stay out of it, fearing that the abuser or those associated with the abuser could harm Sally. But at the same time, deep down, he wants her support and protection.
One possible plot development could be Sally's intense anger and determination to protect Percy. She might seek justice against the abuser, which could lead to a showdown in the fanfic's world. Maybe she teams up with Percy's friends to expose the truth.
Sally could be curious. She might ask Percy a lot of questions about the tattoo, like when he got it, why he got it, and if it has any special significance. She could also be a bit worried if the tattoo is associated with something dangerous or unknown.
Poseidon might be extremely angry. He could immediately seek revenge on the abuser. After all, Percy is his son and he has the power to protect him.
She would probably be furious. Artemis has a strong sense of justice and protecting the vulnerable. So, she would likely immediately start to plan how to deal with those responsible for Percy's abuse.
Fanfiction often takes existing characters and creates new, sometimes dark, storylines. In the case of 'percy abused by sally fanfiction', it could be a way for the author to explore complex and often disturbing themes. Maybe the author wants to show how Percy copes with this difficult situation, or perhaps it's a statement about power dynamics. But again, this is all speculation without actually reading the fanfic.
Percy might be very confused at first. He would wonder why his mother, who has always been there for him, suddenly left. He could start to question if he did something wrong. In some fanfics, he may go into a state of denial, not wanting to believe that she's really gone.
Percy would be extremely angry. He loves his mother deeply, and her disownment would feel like a huge injustice. He'd probably want to immediately go and confront the people who disowned her. Maybe he'd also feel guilty, thinking it's his fault as a demi - god that his mother is in this situation.
Nico might be initially shocked. He could feel a deep sense of anger towards whoever was responsible for Percy's abuse. Then he would probably become very protective of Percy, vowing to keep him safe from any further harm.
She might be shocked and angry. Thalia is a protective character. She could immediately vow to find those who abused Percy and make them pay. For example, she might start by gathering information about the abuse, asking Percy for details in a gentle way to not further traumatize him.
Well, Annabeth is a strong character. When she finds out Percy was abused in the fanfiction, she likely starts by trying to comfort him. She may use her intelligence to figure out how to help him deal with the trauma. Maybe she'll also plot some sort of revenge against the abuser in her own clever way, all while being a great source of emotional support for Percy.