Naruto would probably be angry at first. He's always been a free - spirited person, and being kidnapped by Sasuke, his friend - turned - rival, would surely make him mad. He'd likely try to fight back immediately, using his ninja skills and his never - give - up attitude.
Naruto might initially be shocked and confused. He has always considered Sasuke as a friend, so Sasuke's sudden attempt on his life would be a huge blow. He may try to talk to Sasuke first, to understand why he is doing this.
Naruto would probably be very confused at first. He trusts Sasuke, even if it's a Fem Sasuke in this fanfiction, and he wouldn't expect to be kidnapped by her. So, his initial reaction might be to try and talk to her, asking her why she's doing this.
Naruto would be devastated. Sasuke is his closest friend and rival. He would likely go into a state of deep mourning at first. He might isolate himself for a while, just trying to come to terms with the loss.
He may also choose to defend himself without really fighting back. Naruto values Sakura as a friend and teammate, so he would be reluctant to harm her. He might just try to dodge her attacks and keep talking to her, hoping to snap her out of it.
Naruto's reaction would be complex. He would be devastated because his bond with Sasuke is so deep. However, he also trusts Sasuke to an extent. So, he would be torn between his immediate emotional response of anger and his long - standing faith in Sasuke. He might start to look for clues and evidence, and in the process, he could end up uncovering Kabuto's devious plan while also reaffirming his friendship with Sasuke. He would probably be more determined than ever to set things right and prove Sasuke's innocence if he is indeed innocent.
Sasuke would be furious. He's always been protective of Naruto in his own way. He would immediately start looking for her, using all his skills and resources. He might even go on a rampage if he thought Naruto was in serious danger.
Sasuke could be intrigued. If he comes across a well - written fanfic that really captures the essence of his relationship with Naruto or offers a new perspective on his goals and journey, he might get drawn into it. He might start to think about how these different ideas could fit into his own understanding of his life and the world around him. For instance, if a fanfic shows him a different path he could have taken, it might make him reflect on his choices.
At first, Naruto might be shocked and heartbroken. He has always longed for family acceptance, so being banished by them would be a huge blow. He could feel betrayed and angry, especially if he doesn't understand the reasons behind it.
On the other hand, Naruto could also have some hidden feelings that he wasn't aware of before. So, instead of being angry or shocked, he might start to have a warm feeling inside and start to question his own feelings towards Sasuke.