Maybe he starts to train with one - armed techniques. He could learn from other one - armed ninjas if there are any in the fanfiction world. His friends would also play a big role. They might encourage him to keep going or help him in his training.
Maybe he was protecting someone in Wave. He's always the self - sacrificing type, so he could have put himself in harm's way to save a villager or a friend.
It could make Sasuke more protective of Naruto. Sasuke has always had a complex relationship with Naruto, and seeing him lose an arm would stir up some deep emotions. He might feel guilty, especially if he was somehow involved in the incident that cost Naruto his arm. This could lead to Sasuke staying closer to Naruto and being more open about his feelings.
Well, he might face difficulties in combat. Without his arm, his fighting style would have to change drastically. He may rely more on his ninjutsu and less on physical attacks. Also, his daily life activities like eating or holding things would be a struggle.
With his friends, it might strengthen their bonds. They would be more protective of him and help him in his daily tasks. For example, Sasuke might become more empathetic towards Naruto's situation. His relationship with Hinata could also change. Hinata would be very concerned and would constantly be by his side, offering emotional support.
Well, losing an arm would definitely have a huge impact on his ninja abilities. His ability to perform hand seals would be severely hampered. For example, complex jutsus that require multiple and quick hand seals might become impossible for him to execute. Also, his balance in combat could be affected as he's used to having two arms for movement and defense. He'd probably have to rely more on his legs and other non - arm - related skills.
In the context of the fanfic, it could also impact his relationships. His friends might be overly protective, which Naruto may not like. Or, he could inspire others with his determination to keep going despite his injury. It might also change how he is perceived in the ninja world. Some may see him as weakened, while others could view him as even more of a hero for his ability to persevere.
One possible consequence could be a significant change in his fighting style. He might have to rely more on his left side and develop new jutsu techniques that can be executed with one arm. For example, he could focus on enhancing his Rasengan further to compensate for the loss of his right arm's abilities.
One possible aspect of Finn losing his arm in fanfiction could be how it changes his physical capabilities. He might have to adapt his fighting style, perhaps relying more on his legs or using his remaining arm in more creative ways. For example, he could learn to use his sword one - handed in a whole new way that surprises his enemies.
His relationships would shift in many ways. With his family, if he has one by that point, they would be deeply concerned and try to help him adjust. His comrades in the Hidden Leaf Village would be more watchful over him. Enemies would likely underestimate him at first, which could be both a danger and an opportunity for Naruto. His relationship with the tailed beasts might also change, as they might be sympathetic towards his new disability and offer different kinds of support or advice.