One possible way this fanfic could go is that Minato and Kushina's spirits could be in a state of limbo and they are forced to witness Naruto's abuse. This could lead to a series of events where they try to find a way to communicate with Naruto or influence the situation to stop the abuse. Maybe they reach out to other characters in Naruto's life to help protect him.
Perhaps the fanfic could end with a more bittersweet note. Minato and Kushina are able to stop the immediate abuse, but they realize they can't always be there to protect Naruto. So they pass on their strength and values to Naruto in a more profound way, and he grows up determined to never let anyone be abused like he was.
One possibility could be that in the fanfiction, Kushina and Minato see Naruto becoming a great Hokage, respected far and wide. They might see him bringing peace to the village and forging strong alliances with other nations. This would make them extremely proud as they watch from whatever afterlife or special visionary state they are in.
There's a fanfic called 'Minato's Return'. In this story, Minato somehow returns and gets to see Naruto's growth. It's really interesting to see how he interacts with Kushina, who is also there in the story, and how they both guide Naruto in new ways. The descriptions of their family bond are heartwarming.
Maybe they enlist the help of other powerful ninjas. For instance, they could ask Tsunade for medical support in case Naruto is injured. They could also get intel from Shikamaru, who is known for his intelligence. By gathering a team of reliable and strong ninjas, they increase their chances of getting Naruto back successfully.
In a fanfiction, perhaps Minato and Kushina are resurrected during a powerful enemy attack on the village. Naruto is in the middle of the battle when he suddenly sees his parents. At first, he can't believe it. Kushina runs to hug him tightly, while Minato stands there with a proud look. They then join the fight together, using their combined skills to defeat the enemy and have a moment of family reunion.
One great fanfic could be 'The Family's Bond'. It beautifully portrays Minato and Kushina's love for baby Naruto. It shows their daily life, like Minato coming home from a mission and playing with Naruto while Kushina prepares dinner. The details of their interactions make it a heartwarming read.
One great fanfic is 'The Early Days of Naruto' which beautifully depicts Minato and Kushina's relationship with baby Naruto. It shows their tender moments together and how they start to teach Naruto about the ninja world from a very young age. Another good one is 'Naruto's Family Beginnings' where the focus is more on the family dynamic. You can really feel the love Minato and Kushina have for their baby. And then there's 'Baby Naruto's World' which goes into detail about how Naruto's presence affects the village even as a baby, and how Minato and Kushina are at the center of protecting and nurturing him.
In some fanfics, Naruto might be made to hate Minato and Kushina due to a sense of abandonment. If the story is written in a way that emphasizes how Naruto grew up alone and suffering, he could project his anger onto his parents for not being there for him. For example, he might think that if they were alive, he wouldn't have had to endure the taunts and loneliness in the village.
In a fanfic, Kushina might be depicted as a source of great wisdom for Naruto. Since she was his mother, she could pass on some Uzumaki family secrets or just some motherly advice. Minato could be the guiding force in Naruto's development as a ninja. His skills and experiences could be something that Naruto looks up to. Naruto himself should be a complex character, with his own insecurities and doubts at times, but always pushing forward because of his parents' influence.
On a more personal level, they could face internal guilt. As Naruto grows up and achieves great things on his own despite their neglect, Minato and Kushina may realize what they've missed out on. This realization could cause them a great deal of internal turmoil and regret for not being there for their son when he needed them.