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.
A vampire hunter from Europe who comes to America to help Lincoln. This character could have different techniques and weapons for slaying vampires, and there could be some conflict between their European methods and Lincoln's more improvised style at first, but then they learn from each other and become a great team against the vampires.
In this type of fanfiction, a frequent theme is the re - evaluation of the vampire slayer mythology. Maybe the slayer line is seen as something that is more of a curse than a gift. Also, relationships might be re - imagined. For instance, Buffy's relationships with her friends or lovers could be presented in a much darker or more complex way than in the original series. It's all about taking the established Buffy world and turning it on its head to explore different ideas.
In a fanfiction, Henry could be the central character who has his own backstory explored. For example, we could learn about his first encounter with vampires and how it shaped his determination to fight them. He might also have a love interest who is somehow involved in the vampire - hunting world, and the story could revolve around protecting her while also continuing the fight against the undead.
There might also be some original characters created specifically for the fanfiction. These could be other humans who know about Lincoln's secret or other supernatural beings that are related to the vampire lore in the story.
Another fanfiction concept could be that Kimberly is transported to a parallel universe where vampires rule. She has to find a way to adapt to this new world while also finding a way to use her slayer skills to start a revolution against the vampires.
One common theme is identity. Lincoln has to figure out who he is now as a vampire while still being part of the Loud family. Another is secrecy. He has to keep his vampire nature a secret from his family and friends at first. And there's often the theme of power. His new vampire powers and how he uses or struggles with them.
Yes, there are some interesting ones. You can start by looking on fanfiction platforms like FanFiction.net or Archive of Our Own. Just search for 'Loud House Lincoln Vampire' and you'll likely find a variety of stories with different takes on Lincoln as a vampire in the Loud House universe. Some might focus on his relationships with his family members in this new, vampiric state, while others could be more action - oriented with him facing off against other supernatural beings.
There's also a fanfic where Lincoln discovers he has vampire heritage. In this story, he struggles to keep it a secret from his large family while also exploring his new powers. It's an interesting take on the character as he tries to balance his normal life with this new, supernatural side.
Yes, there are some interesting ones. You can find them on various fanfiction websites. Some focus on Bella using her slayer skills in the 'Twilight' universe combined with the Vampire Slayer concept, creating unique storylines and character developments.