In some fanfictions, Sasuke could be transported back in time to when Naruto was a baby. He then tries to change Naruto's fate by being a positive influence early on. He might teach Naruto some basic ninja skills in a more patient way than the adults in Naruto's life usually do, which could lead to a much stronger Naruto in the future.
One interesting story could be where Sasuke discovers baby Naruto alone and decides to protect him in secret. He uses his skills to keep Naruto safe from any threats in the village while Naruto is still too young to understand.
There might be a fanfiction where Sasuke, in a different timeline, finds baby Naruto and decides to train him from a very young age. This would completely change Naruto's growth and the dynamic between them as they grow older. Sasuke would have to deal with Naruto's childishness while also seeing his potential.
One interesting story could be about Sasuke and Naruto adopting a baby together. They face challenges in raising the baby while also dealing with their own relationship and the reactions of their friends. The baby might have some special powers that they have to help the baby control.
One interesting story could be about baby Naruto and Sasuke meeting for the first time in a unique way, like in a secret forest where they both discover a magical creature together. Their innocent reactions and the start of their friendship in this fanfiction can be really cute.
One interesting scenario could be baby Sasuke and baby Naruto getting into innocent mischief together in the Hidden Leaf Village. Maybe they accidentally let all the chickens loose in the market area while playing a game of chase.
One interesting plot could be baby Naruto and baby Sasuke getting lost in the forest together. They have to rely on their budding instincts and nascent chakra to find their way back. Maybe they encounter some small, friendly forest creatures that help them. Another idea is that they accidentally switch places in the village for a day. This leads to chaos as the villagers react differently to them being in the wrong 'homes'.
One interesting storyline could be Naruto finding baby Sasuke alone in the forest and deciding to take care of him. Naruto, with his big heart, would do his best to protect Sasuke from any harm that might come their way, like facing off against wild animals or rogue ninjas.
One idea could be that Naruto and Sasuke find a baby on one of their missions. They then have to figure out how to take care of it while also dealing with the political implications in the ninja world. Maybe the baby has some special power that attracts the attention of both friends and foes.
Perhaps in this fanfiction, baby Sasuke and Naruto are accidentally sent to a parallel dimension. In this dimension, the ninja world is very different. They have to rely on each other more than ever to survive and find a way back home. Along the way, they meet alternate versions of their friends and foes.
One plot idea could be that in the modern world, Naruto and Sasuke have to raise baby Naruto together. Maybe they're in a world where ninjas are like a secret society within modern society. They struggle to keep baby Naruto's identity a secret while also dealing with their own past traumas and how to pass on their ninja skills in a world full of technology.
Another idea is that baby Sasuke and Naruto are found together by a third party, like a wandering ninja who decides to train them both from a very young age. This would create a different dynamic as they grow up together with a unique set of skills taught by this unknown mentor. They would probably have a stronger bond from the start compared to in the original story.
A possible plot is that the baby's existence causes a stir in the ninja world. Some may see it as a symbol of unity between the Uchiha and Uzumaki clans, while others might fear its power. Naruto and Sasuke then have to deal with political intrigue as they try to raise their child in a peaceful environment. Also, the baby could inherit Naruto's positive attitude and Sasuke's intelligence, which could lead to some really cute and interesting interactions within the family.