I think Kakashi would be a likely candidate to take care of baby Naruto. He has experience leading a team and he's quite responsible. He could use his skills to keep Naruto safe and also start teaching him basic ninja values from a very young age. Also, the Third Hokage might get involved and ensure that Naruto is well - cared for within the village.
His friends like Sakura and Sasuke might step in to take care of him. Sakura, with her nurturing side, could handle feeding and cleaning him. Sasuke, though he might seem reluctant at first, would probably also protect the baby Naruto from any threats.
In the 'naruto becomes a baby fanfiction', it could be that the whole village comes together to take care of him. Since Naruto is the Jinchuriki of the Nine - Tails, the village has an interest in his well - being. Ordinary villagers might offer food and supplies, while ninja like Shikamaru could use his intelligence to figure out the best ways to keep Naruto comfortable and protected. Jiraiya, if he were around, would also be a great caretaker as he has a special bond with Naruto.
Iruka - sensei would be a likely candidate. He has always been like a father figure to Naruto, so he would probably step up and take care of baby Naruto.
Kushina would take care of baby Naruto very tenderly. She would make sure he is well - fed before sleep, perhaps by breastfeeding him or giving him a warm bottle. She'd also check his diaper and change it if needed.
Well, in such a fanfiction, Naruto would likely lose all his skills and knowledge as a ninja. He'd be completely dependent on others for care, like eating baby food and being diaper - changed. Maybe his friends would have to protect him from the enemies who might see this as an opportunity to get rid of him once and for all.
First, Minato would isolate Naruto to prevent the spread of the illness if it was contagious. He'd then research all he could about Naruto's symptoms. He'd make sure Naruto was in a warm and clean environment. Minato would also talk to Naruto, even though he was just a baby, believing that his voice could give Naruto some sense of security. He'd be very gentle when changing Naruto's clothes or cleaning him, always with a loving touch.
His friends would probably take care of him. Midoriya would be very eager to help, using his kind-hearted nature. He would make sure Todoroki is fed and comfortable.
It would likely become stronger. Taking care of a baby together requires a lot of cooperation. They would have to rely on each other more, which would deepen their bond. They'd see different sides of each other, like Naruto's gentle side when he rocks the baby to sleep and Sakura's more motherly instincts.
One possible character could be Jiraiya. He was Naruto's mentor later in life, but in a fanfiction, he could have taken Naruto as a baby. He had a close relationship with Naruto's father, so it would make sense for him to take Naruto under his wing from the start. Another could be Tsunade. As one of the Sannin, she has the power and the means to protect Naruto. Plus, she might have seen it as her duty to take care of the son of her old teammate.
In this fanfiction, Naruto would interact with Vesemir, the old and wise Witcher. Vesemir could see Naruto's potential and help him understand the history and traditions of the Witchers. Naruto would also run into the various monsters in the Witcher world. Instead of just fighting them right away, he might try to communicate with them first, like he did with some of the tailed beasts in his own world. His interactions with these creatures would be unique and could even change the way Witchers view certain monsters.
His friends like Sasuke, Sakura, and Kakashi would surely support him. They have been through a lot together and know Naruto's good heart and leadership potential.
Mercy could also be a great caretaker. She has a nurturing side as a healer. She would be able to make sure baby Junkrat is healthy and well - taken care of, using her medical skills to check on him regularly.