Hermione would be extremely worried. She'd start researching right away, trying to find out all she could about the One Ring. She might try to find spells to contain or protect against its power. As for Voldemort, he would see the One Ring as a tool to gain more power. He would likely be overconfident in his ability to control it, not realizing that the ring could potentially control him instead.
I'm not sure of a specific one off the top of my head, but you can try searching on fanfiction websites like Archive of Our Own or FanFiction.net. Look for tags like 'Harry Potter' and 'ring' to narrow down your search.
The Potter ring might have some sort of magical essence that enhances Harry's natural abilities. Maybe it gives him extra strength or speed when he's in a fight. The grimoire, full of rare spells and knowledge, could change the way Harry approaches magic. He might become more experimental and less reliant on the traditional spells he learned at Hogwarts. This could make him a more unpredictable and formidable opponent to his enemies.
Sure. Fanfiction writers often explore unique concepts, and a ring - focused Harry Potter fanfiction could be quite interesting. For example, the ring could be related to one of the Hogwarts houses, perhaps having been created by a founder. It might hold the key to an ancient mystery within the castle walls. Writers could also tie it to the Forbidden Forest, where the ring has some sort of connection to the magical creatures there.
Often in fanfiction, the ring can be a plot device. It could be that Harry Potter unknowingly has a connection to the ring, and Severus Snape has to keep it from falling into the wrong hands. This creates a situation where Snape has to protect both Harry and the ring, leading to some tense and interesting storylines.
Sure. There are quite a few. However, the quality can vary greatly. Some might focus on how the ring of power could change the power dynamics within Hogwarts. For example, a fanfiction could explore what would happen if Voldemort got hold of a ring of power in addition to his Horcruxes. It could lead to a completely different kind of battle between good and evil in the wizarding world.
Perhaps the One Ring has some sort of connection to Voldemort. Harry, having the One Ring, finds that Voldemort is drawn to it because of its power. This could lead to a new battle where Harry not only has to face Voldemort but also has to decide what to do with the Ring. He might have to journey to find a way to destroy it, just like in the original 'Lord of the Rings' story.
A great plot could be that the ring is a portal - creating device. When activated, it opens portals to different parts of the wizarding world and even some unknown magical realms. A group of dark wizards is after the ring to use it for their evil plans. Harry and his friends are on a race against time to protect the ring and close the portals that the dark wizards have already opened, all while learning about the origin and true power of the ring.
Well, perhaps the One Ring is sent to Hogwarts as a mysterious artifact. Dumbledore, suspecting its great power and danger, enlists Harry to investigate. Harry, being the hero he is, soon realizes that the ring has a will of its own. He has to face the temptation of the ring while also dealing with the ongoing threat of Death Eaters, as the two evils start to intertwine in unexpected ways.