Naruto would likely be excited. He loves his son so much that seeing different stories about Boruto would be like seeing different potential futures for him. He might even get some inspiration from the fanfiction to give Boruto some advice in real life.
Boruto might be in awe. He has always known his father as the Hokage, a powerful and respected figure. Seeing Naruto's past full of struggles, loneliness, and determination would make him realize how far his father has come. It could also make Boruto more empathetic towards Naruto and perhaps inspire him to be more like his father in some ways.
The villagers would likely be in shock. Naruto is a beloved figure, but killing his own son would be a very controversial act. Some might turn against Naruto, believing he has gone too far. Others might understand his reasons if they knew the full story, but still struggle with the morality of it.
If parents come across disturbing content in Descendants fanfiction, they should immediately stop watching it. They can also report the content to the platform where they found it if possible.
Parents can react with understanding. They should create an open environment where the teen feels comfortable to talk. For example, instead of getting angry immediately, they can listen to the teen's feelings and experiences.
Luke might be in awe. He's always been seeking his family and a sense of belonging, so meeting his parents could make him feel complete. He'd probably listen intently to whatever they have to say.
Naruto may also try to find solutions. Despite the heartbreak, his optimistic nature might still shine through a bit. He could start to search for ways to mend the relationship with his parents, whether it's through magic in the Naruto world or by trying to prove his worth to them.
He might be in shock at first. Sly has been on his own for so long that seeing his parents could be overwhelming. He could just stand there, speechless, trying to take in the fact that they are real and in front of him.
Danny might react with panic at first. After all, he has been hiding his identity from his parents for so long. He could try to escape from them, using his ghost powers in a desperate attempt to get away before they can do anything drastic.
Sally would likely be very intrigued. She loves Percy so much and would be eager to explore more of his world through fanfiction. She might be a bit taken aback by some of the more extreme storylines. Poseidon, well, he might see fanfiction as a sort of strange mortal pastime at first. But if he found stories that really delved into his relationship with Percy in new ways, he could become quite interested.