Well, normal Naruto mainly relies on his chakra and the Nine - Tails' power. But Dark Naruto with Eternal Mangekyou Sharingan would have unique visual jutsu. He could use the Sharingan's genjutsu abilities on a much greater scale, perhaps even trapping entire villages in an illusion without them realizing.
Normal Naruto's power is more about his positive energy and his will to protect. Dark Naruto with the Eternal Mangekyou Sharingan would have a more sinister power. His Sharingan could allow him to manipulate the shadows and use them as weapons or as a means of stealth. He could also use the Eternal Mangekyou Sharingan to create portals to different dimensions, which is something normal Naruto can't do without some external help.
Dark Naruto's Eternal Mangekyou Sharingan might give him the power to copy not just jutsu but also the very essence of a ninja's fighting style. So, unlike normal Naruto who has to learn techniques through practice, Dark Naruto could instantly absorb and use an opponent's most powerful moves against them. Also, his Eternal Mangekyou Sharingan could give him enhanced physical abilities like super speed and strength that normal Naruto doesn't have just from his natural abilities.
In Naruto fanfiction, it's often portrayed as extremely powerful. It can give characters abilities like seeing through any illusion, predicting an opponent's moves with near - perfect accuracy.
The Eternal Mangekyou Sharingan is a very powerful and significant element in Naruto fanfiction. It represents a high - level evolution of the Sharingan. In fanfictions, it often gives the characters who possess it extraordinary abilities, like enhanced visual powers, the ability to use unique and powerful jutsus.
Naruto would become more introspective. The power of the eternal mangekyou sharingan often comes with a lot of emotional baggage in the Naruto universe. So Naruto might start to question more about his own identity and his place in the ninja world. He might also become more cautious as he realizes the great power he now holds and the potential for misuse.
With Sasuke, their relationship would become more complex. Sasuke might be both jealous and intrigued by Naruto having the Mangekyou Sharingan. Jealous because it was always an Uchiha thing, and intrigued because he wonders how Naruto will use it. This could lead to more intense rivalries and also more opportunities for them to understand each other better.
In Naruto fanfiction, the Mangekyou Sharingan is sometimes used to create new backstories for characters. For example, a character who didn't have the Sharingan in the original might be given one in the fanfiction, and the story could explore how they came to possess and master the Mangekyou Sharingan. This can add a whole new layer of intrigue to the character.
A possible plot could be that Dark Naruto's Eternal Mangekyou Sharingan has a special power that can merge the minds of people. He uses this to merge with the good Naruto inside him. Through this merge, he battles his inner demons and slowly transforms back to his normal self while also gaining the combined strength of both his dark and light sides.
Naruto's relationship with his friends in the Hidden Leaf Village would also change. Some might be in awe of his new power, while others might be a bit afraid. For example, Sakura might be worried that the Mangekyou Sharingan could change Naruto's personality. Naruto would have to reassure them that he's still the same person. And he might also use his new power to protect them more effectively, strengthening their bond.
Power. The eternal mangekyou sharingan represents a great power in the Naruto world, so many fanfics focus on how characters use or struggle with this power.
For his relationship with Kakashi, it could be complex. Kakashi, having his own experiences with the Sharingan, would be in a unique position to guide Naruto. But at the same time, he might be worried that Naruto's new power could attract unwanted attention. Naruto's bond with the villagers could also be affected. Some might see him as more of an Uchiha than a Uzumaki now, and there could be those who fear his power. His relationship with Jiraiya, if he were still alive in the fanfic, would also change. Jiraiya would need to teach Naruto how to use this power for good and not let it corrupt him.
His relationships would also change. Some of his friends might be a bit wary of him now that he has such a powerful and somewhat feared ability. Naruto would have to work hard to show them that he's still the same Naruto. At the same time, he could form new alliances with those who are interested in his new power or who can help him understand it better. He might also be more isolated at times as he delves deeper into mastering the Sharingan, which would be a big change from his usually outgoing and social self.