In some fanfictions, it could be due to a special jutsu gone wrong. Maybe a jutsu that Kakashi was using to transfer some of his chakra to Naruto for a mission accidentally transferred his Sharingan power as well.
The fanfiction might show Kakashi growing in terms of his understanding of the Sharingan's true nature. As he delves deeper into the abilities of the eternal Mangekyou Sharingan, he could gain a broader perspective on the Uchiha and their powers, which in turn enriches his own character development. He may start to see things from an Uchiha - like point of view, which was previously foreign to him. Also, the new power might attract new enemies or allies, and through these interactions, Kakashi will have to adapt and grow. For example, if new enemies target him because of his powerful Sharingan, he'll need to find ways to outwit them and protect those he cares about. This will surely contribute to his character growth.
There were many explanations for the origin of Lu Liang's dual hands. According to document 1 and document 3, Lu Liang's dual arms were only comprehended after his limbs were cut off and he experienced extreme pain and near-death. Lu Ci cut off his limbs so that he could learn to use both hands. Lu Liang's talent in the Bright Soul Technique was very high. Adding on the fact that he understood the existence of dual hands, it allowed him to grasp this ability. In document 4, it was mentioned that the Lu family's double-handed ability was created by Lu Liang's grandfather, and Lu Liang was the successor of this ability. According to document 6, there were two possible ways for the Lu family to obtain both hands. One was natural reproduction, and the other was genetic modification. However, it was not clear how Lu Liang had mastered both hands. Thus, we have no way of knowing the exact origins of Lu Liang Shuang's hands.
One great fanfiction could be about Kakashi using his Sharingan to train Naruto in a special jutsu. Maybe he shows Naruto how to better perceive an opponent's moves by using the Sharingan's ability to analyze. This could lead to Naruto developing a new and powerful technique that combines his own chakra control with the insights from the Sharingan.
The story might progress as Naruto struggles to control the Sharingan at first. He may have some internal conflict as he tries to incorporate this new power into his existing set of skills. As he gets better at using it, he could start to change the power structure in the ninja world. His relationships with his friends and allies could also be affected. For instance, Sakura might be more worried about him as the Sharingan could put a strain on his body. Naruto could also use the Sharingan to uncover secrets about his parents or the history of the ninja clans that were previously unknown.
There were many theories about the origin of Grand Preceptor Wen's third eye. According to the story of the Investiture of the Gods, Grand Preceptor Wen was born with a third eye, which was called the Eye of Divine Power. It could distinguish between evil and loyalty, as well as the black and white of the human heart. Some legends said that Grand Preceptor Wen's third eye came from Goddess Nüwa, while others said that it was developed by his master, the Golden Spirit Holy Mother. However, the specific details of the origin may vary according to different versions of the story. In short, Grand Preceptor Wen's third eye was a manifestation of his unique ability and magical power, which also made him a well-respected figure in the Investiture of the Gods. As for the specific origin and details, the current search results did not provide a clear answer.
Kakashi's character would likely become more confident in his abilities. With the Dual Mangekyou Sharingan, he has access to greater power, which could boost his self - assurance. He might take on more dangerous missions without hesitation.
One way could be through a kekkei genkai transfer jutsu. If a powerful ninja, perhaps an old hermit with knowledge of ancient jutsus, decides to transfer Sasuke's Sharingan to Naruto for the greater good of the village. This jutsu might be risky but in the world of fanfiction, anything is possible.
One interesting fanfic could be where Kakashi uses his Sharingan in a unique way to train Naruto. Maybe he shows Naruto how to better analyze his opponents' moves just by using the Sharingan's ability to copy and predict. For example, Kakashi could create a special training ground where Naruto has to face multiple clones of himself that mimic the fighting styles of different enemies. And the Sharingan plays a crucial role in Naruto understanding the patterns of these clones.
The consequences could be far - reaching in the fanfiction. Naruto's relationship with Kakashi might change. There could be a deeper sense of respect and a new kind of bond formed because of this transfer. In terms of power, Naruto could unlock new jutsus or abilities that are related to the Sharingan. He might be able to combine his existing Rasengan techniques with the Sharingan - enhanced perception. This could make him an even more formidable opponent. However, it could also put a strain on his body. The Sharingan is known to consume a lot of chakra, and Naruto's body might need to adapt to this new power drain. If he overuses it, it could lead to exhaustion or even long - term damage.