One idea could be that the Goblin Slayer gradually gains the affection of various female characters as they see his unwavering dedication to slaying goblins. For example, a priestess might develop deeper feelings as she witnesses his selfless protection of the village. Another could be a female warrior joining his cause and falling for his combat skills and quiet determination.
Perhaps a plot where the Goblin Slayer unknowingly rescues a princess from goblins. The princess, instead of going back to her castle immediately, decides to follow the Goblin Slayer on his adventures. Along the way, other female characters like an elven archer and a dwarven smith also join them. They start to admire the Goblin Slayer for his courage and tenacity, and a harem - like situation begins to develop as they all vie for his attention in their own unique ways.
One idea could be that Naruto is somehow transported to the world of Goblin Slayer. He could use his shadow clone jutsu to confuse the goblins and then use his rasengan to take out large groups. Another could be that the Goblin Slayer visits Konoha and Naruto has to teach him about the concept of chakra.
For a Goblin Slayer crossover fanfiction, consider a crossover with 'Harry Potter'. The Goblin Slayer could be transported to the wizarding world. He would be confused by the magic there at first, but then realize that goblins also exist in this world. He could team up with Harry and his friends to stop a goblin - related dark magic plot. This would bring a unique mix of the gritty, down - to - earth fighting style of the Goblin Slayer with the magical world of 'Harry Potter'.
How about a crossover with 'Fairy Tail'? The Goblin Slayer's serious and methodical approach to slaying goblins could contrast with the more flamboyant and magic - using mages of Fairy Tail. They could team up to fight goblins that have been magically enhanced or are causing trouble in the Fairy Tail world.
One idea could be a fanfic where the Goblin Slayer has to team up with a young mage who is new to the world of slaying goblins. They start off not getting along but gradually learn to work together and respect each other's skills.
Another great idea for a goblin slayer fanfiction could be a story set in a different region where the goblins have developed unique abilities or behaviors. The Goblin Slayer has to adapt his usual tactics to deal with these new challenges. This could involve exploring uncharted territories and facing goblins that are more organized or have strange powers.
One possible plot could be that the Guardians from Destiny are called to the world of Goblin Slayer due to some strange energy anomaly. They team up with the Goblin Slayer to fight against an army of goblins that have been enhanced by a Darkness - like power. The Guardians' advanced technology and powers would make for an interesting contrast with the more medieval - style combat of the Goblin Slayer.
One idea could be a crossover with Spider - Man in an alternate universe where the Green Goblin teams up with Doctor Octopus against a more powerful and darker version of Spider - Man. They could form an uneasy alliance to take over the city's criminal underworld.
One possible plot could be that the Doom Slayer somehow gets transported to the world of Goblin Slayer. He then uses his advanced weaponry and combat skills to help the Goblin Slayer in his never - ending fight against the goblins. Maybe they team up to take on a super - powerful goblin boss that neither could defeat alone.
One idea could be an OC who has a unique breathing style that combines elements from different existing styles. For example, a mix of water and flower breathing, which could create beautiful yet powerful attacks. Another could be an OC who is a demon but has retained some of their humanity and tries to find a way to coexist with the Demon Slayers. Maybe they form an unlikely alliance with a slayer to fight against more evil demons.
One idea could be that Lincoln discovers a hidden vampire lair beneath the White House. He has to battle the ancient vampires there while also trying to keep his vampire - slaying activities a secret from his political allies.