Use vivid descriptions. Describe the gory and chaotic scenes of the zombie - infested world in detail. When your OC is fighting off zombies, describe the smell of decay, the sound of the zombies' moans, and the feeling of adrenaline coursing through your OC's veins. This will draw the reader in and make your fanfiction more engaging.
Focus on character development. Make your OC have a distinct personality, backstory, and motivation. For example, if your OC has a fear of losing their family which drives them to be extra brave in the face of zombies. This makes them more relatable and interesting.
Incorporate unexpected plot twists. Instead of the usual battles between the factions, have your OC accidentally start a new conflict that no one saw coming, like a conflict over a new type of power source that has emerged in the Highschool DxD world. This will keep readers engaged.
First, give your OC a distinct personality. Don't make them a typical 'good guy' or 'bad guy'. Maybe they have a sense of humor that's a bit dark or they're overly polite in a world full of brash characters. Second, their power should have a unique origin. It could be something like they got their power from an ancient artifact that was lost in the 'Highschool DxD' world.
First, focus on creating a unique backstory for your OC. For example, if your OC has a tragic past that led them to be who they are in the Highschool DxD world, it can make them more interesting. Second, give your OC distinct abilities or powers that are not commonly seen in the series. Also, develop their personality in a way that makes them different from the existing characters. They could be extremely introverted or have an unusual sense of humor.
Give your OC a distinct personality. For instance, if most characters are bold and brash, make your OC more reserved and calculating. This contrast will make them stand out.
To make your Highschool DxD OC Annihilation Maker Fanfiction stand out, you can give your OC a really unique power or ability. Something that no one has seen before in the Highschool DxD universe. For example, a power that can manipulate time in a completely different way than what's already in the series. Another way is to have a very unexpected plot twist. Maybe the OC who was thought to be on the side of the devils turns out to be working for a completely different and hidden force. This will keep readers on their toes.
To make it stand out, you need to do in - depth research on the Ouran Highschool Host Club world. Know the existing characters well so that your OC can interact with them in a believable way. For the yaoi aspect, don't just rely on clichés. Try to explore deeper emotions and the cultural context behind male - male relationships. You could also incorporate some beautiful and detailed descriptions of the school and its events to create a vivid setting for your story.
Also, pay attention to the world - building. Since Highschool DxD has a rich and complex supernatural world, add more details to it in your fanfiction. Describe new locations, hidden powers, or ancient artifacts that haven't been explored in the original series. By expanding on the world, you make your story more immersive and unique.
Create strong relationships between your OC and the existing characters. Don't just have them tag along. Have them interact in meaningful ways, like having deep conversations, sharing secrets, or having conflicts that are resolved in an interesting way. This will make your OC more integrated into the story.
First, develop a really unique character design for your OC. Give them distinct physical features, like a troll with glowing crystals on their body or a human with a strange birthmark that has a connection to the troll world. Second, focus on an original plot. Don't just follow the typical good - vs - evil story. Maybe your OC has to solve a mystery that involves both troll and human cultures. Third, use vivid descriptions. When you describe the troll world or the actions of your OC, make the reader feel like they are there.
Develop a unique backstory for your OC. Maybe they grew up in a different culture than the other characters in Persona 3. This could influence their values, their fighting style if they get a Persona, and how they interact with others. They could have a family history that ties into the overall lore of the game in an unexpected way. For instance, their ancestors were involved in the first battles against the Shadows. This would not only make them stand out but also add depth to the fanfiction.