Yes, there are likely some 'Naruto Son of Evil Minato' fanfictions out there. Fanfiction websites are full of various creative takes on the Naruto universe. You can start by checking popular fanfiction platforms like FanFiction.net or Archive of Our Own. Just search for the specific title or relevant keywords to find ones that match this concept.
Well, perhaps the plot could involve Minato having a secret evil plan all along. He could have used Naruto as part of this plan without Naruto knowing. Naruto then starts to notice strange things related to his father. As he digs deeper, he finds out about Minato's true nature. This could lead to Naruto having to choose between following in his father's footsteps (for some strange reason like power) or defying him and becoming a true hero on his own terms. The story could also involve Naruto's friends either turning against him because of his relation to Minato or helping him to overcome this difficult situation.
One possible fanfiction could be where 'evil Minato and Kushina' are under some sort of dark magic or mind control. They find Naruto not as their beloved son but as a target. Maybe they are being manipulated by a powerful enemy of the village who wants to use Naruto's power for evil. However, Naruto's pure heart and the bonds he has formed with his friends start to break through the false personas of his parents.
Sakura could be a significant character. In the context of Naruto being Minato's son, her relationship with Naruto might change. She could be more in awe of him at first or have different expectations. Also, Sasuke is likely to be a main character. His rivalry with Naruto could take on new dimensions as Naruto has the added legacy of being Minato's son. Their battles and interactions might be more intense and influenced by Naruto's heritage.
The relationship can be developed by having Minato appear in Naruto's memories more vividly. For example, Naruto could start having flashbacks of Minato's training sessions or family moments that he didn't know about before. This would make Naruto feel closer to his father.
One possible fanfiction could be about Kagome somehow traveling to the Naruto universe. Maybe she meets Minato and they form an alliance. And she discovers that Naruto is Minato's son. Shippo could be a unique addition, perhaps he has some special abilities that are useful in the Naruto world.
Some fanfictions focus on Naruto's relationship with the village. As Minato's son, the villagers' perception of him could be different. They might have higher expectations from the start. This could lead to Naruto either struggling more with the pressure or using it as motivation to prove himself even faster. There could also be stories about Naruto uncovering secrets about his father that were hidden from him in the original story.
Naruto would likely be extremely confused at first. He has always idolized his father, and to have Minato do such a thing would shatter his perception. He'd probably try to talk to Minato, ask him why he's doing it.
Well, the story could develop in many ways. Maybe Naruto could be an orphan found by someone else in the village, like an old ninja who decides to train him in secret. This would change Naruto's backstory completely. He might not have the same kind of pressure or expectations that come with being the son of a famous Hokage. His character could grow in a different direction, perhaps being more independent from the start as he has to create his own identity without the shadow of his 'father' Minato.
Perhaps Minato has been corrupted by power. In the fanfiction world, he might have come across some source of power that has twisted his mind. By sealing Naruto's chakra, he could be trying to take that power for himself. It could also be related to some prophecy that he misinterprets. He thinks sealing Naruto's chakra is the key to saving the world, but in reality, it's the opposite.