In some fanfictions, they might show Harry having dark powers through things like unexpected magical outbursts with a malevolent tinge. For example, he could accidentally use a spell that causes harm in a way that seems to draw on darker magic. However, in the original series, Harry is firmly on the side of light magic, so this is a departure in fanfiction.
You can try some popular fanfiction websites like Archive of Our Own (AO3). It has a wide range of fanfictions, and you can search specifically for 'dark mc fanfiction' using the search bar. There are often filters you can use to sort by popularity or recency.
Naruto was an anime where the male lead had super powers from the beginning. The male protagonist, Naruto Uzumaki, showed amazing talent in ninjutsu when he was young and met his mentor, Selaiya, at the ninja school. Under the guidance of Yukiya, Uzumaki Naruto gradually grew into a powerful ninja and possessed various super abilities such as Shadow Clone Technique, Spiral Pill, etc.
Often, in these fanfictions, the discovery of a new, ancient and dark magic artifact can be a plot device. Harry might find this artifact and, as he tries to understand or control it, he starts to develop dark powers. Also, the idea of a prophecy misinterpreted can play a role. A prophecy that was thought to be about his heroism is actually about his fall to the dark side, leading him to explore and use dark powers.
Dark secrets are also frequently present. Each character may have a past they are trying to hide or a personal agenda that adds to the overall mystery and darkness of the story. For example, a character might be involved in illegal activities on the side that could put the whole MC in danger if discovered. Additionally, the sense of brotherhood in these novels is often explored in complex ways. It's not always a simple, harmonious bond. There can be jealousy, betrayal, and competition within the group, all while they present a united front to the outside world.
There were some novels that met the requirements for the main character to have the ability of the MC world. Among them," Doomsday: I Have the Right Hand of MC " was a novel about the protagonist who had the ability of MC in an apocalyptic world. In addition," Miracles Of Ridiculous " was also a novel in which the main character had the MC ability. It included elements such as Silver Soul, Harry Potter, and a full-time hunter. In addition, novels such as Minecraft's Wandering Worlds, MC: Nation Building, Minecraft: My Daily Life at Marvel also met the requirements. However, these search results did not provide a detailed description of the plot, so they could not provide more information.
A mentor figure could be the one betraying the mc. The mc trusted this mentor completely, but the mentor has some hidden motives. Maybe they are working for a greater evil and see the mc as a threat or a tool to be used, so they betray the mc, which then causes the mc to turn dark.
The mc ride manga and anime are related, but the anime can make changes to enhance the viewing experience. Sometimes characters' expressions or actions might be emphasized differently.
One great anime is 'Sword Art Online'. The main character, Kirito, is extremely overpowered (OP). He is highly skilled in the virtual reality world of SAO. In the series, he also has a love story with Asuna. Their relationship develops as they face various challenges together in the dangerous game world.
The theme of secrecy is quite prevalent. The MC has its own set of rules and secrets, and when a romance blossoms, these secrets can either bring the couple closer or tear them apart. Another theme is the idea of the outsider. Often, the female lead is an outsider to the MC world, and her entry into this world and relationship with an MC member is a central part of the story. Also, the theme of family, not just in the traditional sense but also the MC as a family, plays a role in the relationships and the overall story.