One interesting aspect of Valentino fanfics could be his business dealings in Hell. Maybe a fanfic shows him making a new deal with a rival or trying to expand his empire. Another idea could be a fanfic where Valentino has a change of heart, which would be quite a twist considering his character.
One plot idea could be that Valentino and Vox form an unexpected alliance to take over a new part of Hell. They might start by manipulating some of the lower - class demons to do their bidding. Another could be a story where they both have a falling out over a shared interest, like a powerful artifact in Hell, and then compete against each other in a series of challenges. A third idea is that they have to team up to face a common enemy, perhaps a new demon who is threatening their power and status in Hell.
I'm not sure of a specific one off - hand, but you can start by looking on fanfic platforms like Archive of Our Own. There are usually tags for Valentino and Hazbin Hotel that can help you narrow down your search. Just look for ones with high ratings and good reviews.
The popularity might be due to the complex and interesting characters of Vox and Valentino. Their personalities in the show are full of mystery and charm, which gives fanfiction writers a lot to work with.
One popular 'Hazbin Hotel' tickle fanfic might be those that focus on the unique character dynamics. For example, fanfics that explore the interactions between Charlie and Alastor in a ticklish situation can be quite interesting. The humor and playfulness added by the tickle concept can bring a new dimension to their relationship as seen in the series.
One popular 'Lucifer Hazbin Hotel' fanfic might be those that explore the backstories of the characters in more depth. For example, a fanfic could focus on Lucifer's past and how he came to be in charge of Hell. It might add more details about his relationships with other demons and his role in the hierarchy.
The relationship could be developed through shared goals. For example, if they both want to expand their influence in Hell, they might start by making small deals with each other. Then, as they see that they can benefit from working together, their relationship could grow. Another way is through conflict. Maybe they start by hating each other, but as they face challenges together, they start to respect each other more.
You could also write a fanfiction about a new character arriving at the Hazbin Hotel. This new character could have a unique power or a very different personality from the existing ones, which would create all sorts of new interactions and storylines. Maybe they have a special ability to see the pasts of the other characters and use that to help them on their path to redemption.
One idea could be exploring the backstories of the characters in more depth. For example, delving into how Alastor became the Radio Demon. Another could be creating a new character who arrives at the hotel and causes a stir among the existing residents. Maybe a character from a different dimension or with a very unique power.
You can try fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including Hazbin Hotel. Just use the search function and type in 'Vox x Valentino' to find relevant stories.
You could write a fanfic about a competition among the demons in the Hazbin Hotel. They could compete in various challenges that test their skills, whether it's singing, dancing, or something more devious. The winner could get a special prize, like a one - day pass to visit the human world or a chance to be upgraded to a better room in the hotel. This would show different sides of the characters and create a lot of interesting interactions.