One idea could be that Naruto inherits Tsunade's incredible strength and medical ninjutsu skills. Maybe in the fanfiction, he uses these skills in a new and unique way during battles, combining his own Rasengan - like techniques with Tsunade - style brute force punches. He could also use the medical ninjutsu to heal his friends more effectively, even in the heat of battle.
In this fanfiction, Naruto might also have a different training regime because of his relation to Tsunade. Instead of just training with Jiraiya, he could also train with Tsunade. She could teach him how to better control his chakra for both combat and healing purposes. And perhaps there could be a sub - plot where Naruto discovers some long - lost Senju techniques that only Tsunade knew about, which would make him even more powerful.
Another aspect could be the family dynamic. Since Tsunade is his grandmother, she might be extremely protective of Naruto. This could lead to some interesting storylines where she tries to shield him from danger but Naruto wants to prove himself independently. Also, Naruto could learn about the Senju clan's history from Tsunade, which would give him a new perspective on his own power and place in the ninja world.
The story could also change in terms of Naruto's power development. With Tsunade as his grandmother, he might have access to more advanced medical ninjutsu earlier. This could be crucial in some battles. For example, in the fight against Pain, he could have not only saved the village but also healed many more people quickly. And his understanding of chakra control, which is important for Tsunade's techniques, could make his regular jutsu more powerful too. He could learn to infuse his Rasengan with the same kind of chakra control that Tsunade uses for her super - strong punches.
In a fanfiction where Naruto is Tsunade's son, his training regime would be very different. Tsunade would likely push him hard in both physical and medical training. Naruto might have access to resources that he didn't have in the original story. For example, he could study ancient Senju clan jutsu from a young age. His appearance might also be different, perhaps having some of Tsunade's features. His hair color or eye shape could be influenced by her genetics. Moreover, the village's perception of him would change. People would see him as not just the Jinchuriki of the Nine - Tails, but also as Tsunade's heir, which could bring both advantages and disadvantages in terms of how they interact with him.
Well, Naruto would probably have a different upbringing. Tsunade could teach him her gambling skills, for better or for worse. He might also be more confident in his abilities from the start, since Tsunade is a very self - assured person. And he could have a different relationship with Jiraiya. Maybe Jiraiya would be more cautious around Naruto, knowing that Tsunade is his mother.
Tsunade would probably be very suspicious at first. Naruto suddenly appearing from the future? It's not something that happens every day. She might think it's some kind of enemy's trick or a genjutsu.
One idea could be that Naruto discovers his Senju heritage through an ancient scroll. Maybe Jiraiya had found it long ago but only now does Naruto unlock its secrets. This could lead to Naruto having new abilities related to the Senju clan, like enhanced wood - style techniques.
Well, Naruto could warn Tsunade about future disasters. Maybe he tells her about Pain's attack on Konoha in advance, so she can better prepare the village defenses. This would change the course of many events and save a lot of lives.
One possible way the storyline could develop is that Naruto would inherit some of Madara's powerful chakra and Sharingan - like abilities. Since Tsunade is known for her medical ninjutsu and superhuman strength, Naruto might also have a natural affinity for healing. This could lead to a new type of combat style for Naruto, where he combines his inherited skills with his own Rasengan - based techniques. He could use his Sharingan - like power to predict his opponents' moves and then counter with his Rasengan, while also being able to heal himself or his comrades in the heat of battle.
Another aspect could be the family history. Since Naruto is the grandson of the Fem Kyuubi, there could be a whole backstory about how his parents met. Maybe his mother was a normal human who had a special encounter with the Fem Kyuubi's son (Naruto's father). This could add a lot of depth to the Naruto universe and also explain some of the unique traits Naruto has that are not present in the original story.
In a fanfiction, Naruto could inherit some of the combined traits of Hashirama and Madara. For example, he might have Hashirama's ability to connect with nature on an even deeper level, while also having Madara's strategic mind. This would make him an even more formidable ninja. He could use these newfound abilities to face new and stronger enemies, like an ancient evil that once threatened Hashirama and Madara.
Perhaps in this fanfiction, there's a secret prophecy about Naruto being the grandson of Madara and Tobirama. This leads to a lot of political intrigue within the village. Some people want to use Naruto for their own gain, while others are afraid of what his true heritage might mean for the future of the Hidden Leaf.