In certain fanfiction concepts, Naruto might make a deal with some sort of spiritual entity. He sacrifices something of his own, like a part of his power or his future, in order to bring Kushina and Minato back. Or he could have harnessed the power of the tailed beasts in a new and unique way. The tailed beasts are extremely powerful, and if he could combine their power with his own in a specific way, it might be enough to revive his parents.
In certain fanfic concepts, Naruto could have found a special relic or artifact. This relic might have the power to reverse death. Since Naruto is always on adventures and exploring different places, he might stumble upon such an item and use it to revive Kushina. It could also be related to the Uzumaki clan's secrets that he uncovers which enables him to bring his mother back.
It could change the power balance in the ninja world. Other villages might see Konoha as a much greater threat with Minato and Kushina back. On the other hand, it could also lead to more cooperation as they might be seen as a symbol of hope. Emotionally, for Naruto, he would be able to learn more about his family, his heritage, and maybe even get some long - awaited parental guidance which would further develop his character.
In some fanfictions, Naruto might use some super powerful jutsu he created or mastered. Maybe it's a new form of Sage Mode that can reverse time on a small scale. Another possibility is that he found some ancient forbidden technique hidden in the Uzumaki clan's secrets.
In some fanfictions, Naruto might use his strong influence and the power of his bonds. He could convince the other villages to help, pooling resources like building materials and ninja manpower. With his own Uzumaki heritage and knowledge of Uzushiogakure's past, he'd guide the reconstruction process.
In some fanfictions, Naruto might use a powerful jutsu. Maybe he discovers an ancient sealing technique that can bring back the dead for a short time. He could also have found some rare chakra-infused artifact that has the power to revive the First Hokage.
At first, Naruto and Kushina might start to distance themselves from Minato. They could avoid him and not talk to him as much. As time goes on, the hatred might grow deeper. Naruto could start to oppose Minato in public or in important village matters. Kushina might also try to influence others in the village against Minato.
In some cases, Naruto might initially become bitter towards his parents. But as he experiences more in life and learns about the possible reasons behind their actions, he could come to understand and even forgive them. His reaction would also depend on the people around him. If he has good friends or mentors, they could help him deal with his emotions in a more positive way.
She could use her Uzumaki chakra chains to break through any barriers or enemies in their way. Maybe she also has some secret teleportation jutsu that she uses to quickly get away with Naruto.
Perhaps Naruto finds a way to travel back in time and prevent Kushina's death in the first place. He could use his Sage Mode or some other special ability to manipulate time. And then, by changing the past, he effectively'revives' her in the present. In the Naruto universe, there are all kinds of crazy powers, so time - travel isn't completely out of the question.
Well, in some versions, Naruto might use his powerful jutsu. Maybe he uses his Rasengan to fight off the Kumo ninjas who are after Kushina. He could also use his speed and agility to outmaneuver them and get Kushina to safety.