He might be shocked. Fanfiction can often be quite different from the original source material, and the nogitsune concept is already pretty out - there. So the shock value could be high.
When Jackson discovers the nogitsune fanfiction, he could have a range of reactions. If he is a creative person himself, he might admire the imagination of the fanfiction writers. He may start to think about how he could contribute to the fanfiction world too. However, if he has a more traditional view of the story, he could be disappointed or even a little angry that the fanfiction is taking liberties with the nogitsune concept. He might feel that the fanfiction is diluting the authenticity of the original idea, especially if he is a die - hard fan of the original work that the nogitsune comes from.
Jackson's reaction could be mixed. He may be curious about the creativity shown in the fanfiction, especially if it presents new and interesting angles on the nogitsune. But at the same time, he might be a bit skeptical if the fanfiction goes against what he believes are the core elements of the nogitsune in the official story.
If Jackson finds out about the nogitsune fanfiction, it could have different outcomes. For one, if he is a big fan of the original story that the nogitsune is from, he might be excited to see new takes on it. However, if he has a more conservative view of the source material, he might not like how the fanfiction is changing or adding to the lore. He may also feel a bit protective of the original story and characters, and think the fanfiction is distorting them.
In many fanfictions, Naruto's reaction is a mix of shock and determination. The shock comes from finally learning about his clan, and the determination is to uphold the Uzumaki name. He could start wearing something that represents the Uzumaki clan, like a symbol on his clothing. He also may become more protective of the Uzumaki secrets and legacies he discovers.
Steve is usually shocked and conflicted. He might question a lot of things and have mixed emotions.
He would be very angry. Naruto is not one to take betrayal lightly.
In some fanfictions, Vegeta is initially shocked. He might stand there in silence for a moment, his eyes wide. Then he could feel a strange mix of emotions, like pride and fear. He's proud to be having a child with Bulma but also fears for the safety of his family given his dangerous past and the many enemies he has.
Often, Gwaine reacts with acceptance. He's not the type to shun Merlin just because of his magic. Instead, he'll likely embrace it as part of who Merlin is. He could say something like 'Merlin, your magic doesn't change a thing between us. You're still my friend.'
Paul could react with disbelief. He might think it's all some sort of elaborate joke or Percy's wild imagination. After all, the idea of demigods and Greek gods being real is quite far - fetched for a normal mortal like him.
In other cases, Teela's reaction could be a mix of emotions. She could be happy that Adam is such a powerful hero but also a bit sad that he felt the need to keep it a secret from her. This discovery might make her question their entire relationship up to that point, and she may need time to sort out her feelings about it all.
He would likely be initially shocked but then filled with joy. He might become very protective, using his skills to keep the pregnant person safe from any harm in the dangerous Middle - earth setting. He could also start making plans for the future, like finding a safe place for the family to live.
Erik may initially be in disbelief. He could think it's some kind of trick or misunderstanding. He might start investigating, trying to find out if it's really true. He could look into Peter's past, talk to people who knew Peter's mother, etc., to confirm the truth of this revelation.