One interesting idea could be the redemption of a villain like Orochimaru. In fanfiction, he might be redeemed by Naruto's unwavering belief in people's ability to change. Naruto could show him a different path, one of using his knowledge for good, like helping to heal the wounded instead of creating dangerous jutsu for destruction.
Another aspect could be the redemption of Sasuke in a different way. Maybe in the fanfiction, Sasuke realizes his mistakes earlier and tries to make amends not just to Konoha but to all the villages he has wronged. He could start by teaching the next generation his skills and sharing his experiences to prevent others from going down the wrong path.
One idea could be a fanfiction about an alternate ending where the main character chooses a different path. For example, instead of following the main storyline's conclusion, they decide to start a new life away from all the chaos. Another idea might be a story that focuses on a minor character from the game and gives them a more in - depth backstory and their own adventure. Maybe a story about a young outlaw who is trying to make a name for himself in the world of Red Dead Redemption.
One idea could be exploring the backstory of a minor character in the game. For example, the life of a random outlaw in the gang before they joined. Another could be a what - if scenario, like what if Arthur Morgan didn't get sick. And also, you could write a fanfiction about the relationship between different characters, such as Dutch and Hosea when they were younger.
Well, a cool crossover fanfiction idea could be with 'The Witcher'. Geralt could find himself in the world of Red Dead Redemption, hunting monsters in the American frontier. Or, for a more comical crossover, think about a crossover with 'SpongeBob SquarePants'. SpongeBob and Patrick end up in the wild west and their naivete causes all sorts of chaos among the outlaws. Also, a crossover with 'Harry Potter' could be interesting, with wizards and witches showing up in the world of Red Dead Redemption and causing a stir with their magic.
One idea could be a character who has made major mistakes in the past trying to atone by using their magic for good deeds in the Fairy Tail guild. For example, a former dark mage could start helping with guild repairs and protecting the town from small threats.
One idea could be focusing on a character's journey to redeem themselves from past mistakes. For example, Alison could be working hard to make amends to the other Liars for all the lies and pain she caused in the past. She might volunteer in the community or be extra kind to them.
One interesting idea could be the combination of Naruto's ninja skills with mecha technology. For example, Naruto might use his chakra to power up the mecha in unique ways. Another idea could be the new enemies that are created specifically for this mecha - Naruto concept, like robotic shinobi that require different combat strategies compared to normal foes. Also, the design of the mecha Naruto itself can be really cool, perhaps with features inspired by the Nine - Tails.
One idea could be that the protagonist from Infamous somehow gets transported to the world of Red Dead Redemption. Maybe they have to adapt to the old - west setting and deal with outlaws while also trying to find a way back home. Their electrical powers would be a huge shock to the cowboys and bandits.
One idea could be that Cinder realizes the true cost of her actions after seeing the destruction she has caused on a personal level. For example, she might encounter a family that has been torn apart because of the events she set in motion. This could be the start of her journey towards redemption.
Another idea is that Aizen somehow ends up in the Naruto universe during the time of the Fourth Great Ninja War. He could try to manipulate both sides for his own gain. But Naruto, with his ability to see the good in people, might try to reason with Aizen and show him a different path. It could be a story of redemption or a great battle if Aizen refuses.
In a 'Naruto Mermaid Fanfiction', the mermaids could be in danger from an evil organization that wants to capture them for their precious scales. Naruto teams up with a mermaid princess to stop this threat and in the process, they learn about each other's worlds.