Perhaps Sakura could time travel and find out that she has a special connection to a powerful warlord in the warring era. Maybe she was a reincarnation of someone important to him, and their meeting would set off a chain of events that could either bring peace or more chaos to the era. For example, she might influence his decisions on alliances and battles.
One plot idea could be Sakura traveling back to the warring era and using her modern medical knowledge to save the lives of many soldiers. This would not only change the course of small battles but also gain her the respect and protection of different warring factions.
Another idea is that Sakura time travels and discovers a hidden magic or power in the warring era that was lost in modern times. She then has to learn to control this power while also dealing with the politics and warfare of the time. She could use this power to try and end the war, or she might be hunted by those who want to use it for their own gain.
One idea could be that Sasuke and Sakura travel back to the time when the Uchiha clan was still alive. They could try to prevent the massacre. Sasuke might have the chance to talk to his parents and change the fate of his family. Sakura could use her medical skills to help those who were injured during that chaotic time.
A power - hungry warlord who sees Sakura as a threat to his plans of total domination could be the main antagonist. He might fear that her knowledge or the changes she brings could disrupt his hold on power, so he tries to eliminate her at every turn.
One idea could be a story where a young Sakura discovers she has a hidden power that can change the balance of power in the Warring States period. She then has to decide whether to use it for her own clan or for the greater good of all the warring factions.
One interesting character could be a powerful warlord. The contrast between Sakura's modern sensibilities and the warlord's traditional, often harsh, leadership style would create a lot of tension and potential for character development. Another could be a mysterious healer. Sakura could learn from the healer's ancient medical knowledge, and they could form a bond over helping the wounded in the war - torn land. A young and idealistic warrior who is new to the ways of war could also be a great pairing. Sakura could inspire the warrior with her modern ideas of peace and justice.
Well, it could be about Team 7 going back in time to the Warring Era. Maybe they would try to change certain events that had a big impact on the future of their world. They might meet their ancestors or important figures from that era and get involved in epic battles.
Another idea is that Naruto goes back in time and teams up with a young and idealistic member from each warring clan. Together, they form a sort of secret alliance with the goal of promoting peace. They face many challenges, like convincing the more conservative and power - hungry members of their clans that peace is a better option. Along the way, Naruto also has to deal with the fact that his presence in the past might be changing the future in unexpected ways.
A third idea is to create a story centered on the role of women in the Warring States Era of Naruto. Women were often overlooked in the original series, but in a fanfiction, we could explore how female ninjas in different clans contributed to the war effort, whether it be through espionage, combat, or strategic planning.
One idea could be Sakura traveling back in time to her genin days with the knowledge she has now. She could use this to train harder and avoid some of the mistakes she made before. For example, she might focus more on her taijutsu skills from the start.
One idea could be Sakura traveling back to the time of the founding of the Hidden Leaf Village. She could use her modern medical knowledge to help during that era, and perhaps even change the way ninja training incorporated medical skills. Another plot could be her traveling to a time when a great war was about to start, and she uses her skills to prevent it by bringing the different sides together through her diplomatic skills and understanding of different ninja clans.
Another plot could involve them traveling to a time when their own clans were in a different state. For Sakura, she could see how the Haruno clan was more prominent in the past. Shisui could witness the Uchiha clan before all the unrest. They might get involved in family affairs and end up changing the future relationships within their clans in unexpected ways.