One possible plot could be that Naruto uses the Infinity Gauntlet to bring peace to the ninja world. He might snap his fingers and make all the hatred and grudges disappear. With the power of the Infinity Stones, he could also restore all the lives lost in the previous wars, like bringing back his parents and all the fallen shinobi. This would completely change the power dynamics in the Naruto universe and lead to a new era of unity among the different villages.
Well, in this fanfiction, perhaps the Infinity Gauntlet is brought into the Naruto world by a mysterious portal. Naruto, being the curious and brave ninja he is, picks it up. He might initially struggle to control the stones' powers as they are different from chakra. But as he learns, he could use it to unite the shinobi clans in a way never seen before, like using the Time Stone to show the clans the history of their pointless feuds and convincing them to work together for a better future.
Naruto would become more confident, not just in his abilities but also in his decision - making. Having the Infinity Gauntlet gives him an edge that no one else has. He might become a bit more reserved as he has to be careful with the power he wields. He can't just rush into things like he used to.
The plot might involve Harry accidentally stumbling upon the Infinity Gauntlet in the Room of Requirement. As he tries to figure out what it is, he discovers its immense power. However, the Ministry of Magic wants to use it for their own gain. Harry has to decide whether to keep it safe from the Ministry or use it himself to finally defeat all the dark forces that still lurk in the wizarding world.
Well, it could be about Percy finding the Infinity Gauntlet in the world of Greek mythology. Maybe he has to figure out how to use its power without being corrupted by it, all while facing off against some of the most powerful Greek monsters and gods who also want the gauntlet for their own purposes.
Madara Uchiha could be a great antagonist. He already has powerful jutsu and a thirst for power. If he gets wind of the Infinity Gauntlet, he would surely try to take it for himself to achieve his goal of creating a world under his control.
In this fanfiction scenario, Naruto finding the Infinity Gauntlet could lead to some interesting battles. He could use it against his toughest enemies like Madara or Kaguya. But he'd also have to deal with the fact that the Infinity Gauntlet comes from a different universe with different rules. He might struggle to control all the power it holds at once.
One possible plot could be that the male reader is an ordinary person who suddenly finds himself in possession of the Infinity Gauntlet. He has to figure out how to control its power while being hunted by various powerful forces who want the gauntlet for themselves.
In this fanfic scenario, the Infinity Gauntlet could also attract the attention of the White Walkers. If they got hold of it, they could use it to spread their icy grip across all of Westeros and beyond. They might use the Space Stone to teleport their armies, or the Time Stone to reverse the defeats they've suffered, making them an even greater threat to the living.
Well, if Naruto had the Infinity Gauntlet, the story would change drastically. First, he could easily defeat his enemies like Madara or Kaguya with just a snap. No more long and arduous battles. Second, the power dynamic in the ninja world would be completely shifted. Naruto might use the gauntlet to bring true peace, not just the temporary peace they had before. He could potentially reshape the world according to his ideals without having to convince others through his usual means of talk and fight. Third, his friends might view him differently, perhaps with a bit of fear or awe. But Naruto being Naruto, he would still try to use the power in a positive way, but it would be a whole new ball game in the Naruto universe.
He might find it in a hidden chamber in Hogwarts. Maybe it was left there by a powerful wizard from long ago who had some connection to other universes.