Sasuke might be in shock at first. He can't believe that Naruto is dying in his arms. He may feel a great sense of guilt, thinking that he could have done more to prevent it.
Kakashi is often a popular character. He has a lot of knowledge and skills, and his presence can add an interesting dynamic. He might be the one to discover Naruto and Sasuke's time - traveling secret and help them navigate the changes they're trying to make. Another one could be Sakura. She might be involved in different ways, like trying to figure out why Naruto and Sasuke are acting so differently due to their time - traveling knowledge.
Often, there's a theme of family acceptance. Since their relationship is rather unique in the Naruto universe, the fanfiction may focus on how their friends and family react to Sasuke being pregnant. There could also be themes related to protecting the unborn child from potential threats in their dangerous world.
One common theme could be the relationship development between Naruto and Sasuke in this unique situation. It might explore how they deal with the new responsibilities and changes in their lives. Another theme could be the reactions of their friends and the wider Naruto world to Sasuke's pregnancy.
Kakashi is a great addition. He has a long history with both Naruto and Sasuke and can act as a mentor or a source of wisdom. Sakura can also be included. Her relationship with both Naruto and Sasuke adds depth to the story. She can be a strong female character who helps or challenges them. Shikamaru is another good one. His intelligence can bring new perspectives to the plot.
Sasuke's reaction could be complex. At first, he would be enraged. After all, the Rinnegan is a symbol of his power and his journey to gain strength. However, he might also have some mixed feelings. He and Naruto have a deep bond, and he might wonder if Naruto had a good reason for taking it. But overall, his initial reaction would likely be one of fury and a desire to get his power back.
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.
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.
In some cases, Sasuke could be angry. He might see Naruto's request as a sign of weakness or as Naruto giving up too easily. He could lash out at Naruto, telling him to fight instead of asking for death. However, he would still be deeply troubled by the request and would probably struggle with it for a long time, constantly thinking about whether or not he should consider it.
Sasuke would be completely shattered. His world would be turned upside down. He had always seen Naruto as a rival, but also as someone important. Naruto sacrificing himself for him would make Sasuke reevaluate his entire life. He would feel an overwhelming sense of guilt and would likely isolate himself from others. However, over time, he would start to use Naruto's sacrifice as a motivation to become a better person and to protect the things Naruto held dear. He would start to follow in Naruto's footsteps in terms of values like friendship and loyalty, and would try to make amends for his past mistakes.