One popular idea could be the interaction between different species from the 'angel bones' universe and characters from the crossover universe. For example, how an angel character might react to a magic - using character from another world.
There could also be new characters created specifically for the fanfiction. These characters might be hybrids of the two universes, having traits from both 'angel bones' and the crossover world. They could play a crucial role in bridging the gap between the two different settings and storylines, adding a new dynamic to the narrative.
There's also 'Bones Meets Buffy'. In this fanfic, the two universes collide when a series of murders in Buffy's Sunnydale seem to have a connection to some archaeological finds that Bones is researching. It's a fast - paced story that keeps you on your toes. The author does a good job of maintaining the personalities of both sets of characters. For example, Bones is as logical and matter - of - fact as ever, while Buffy is her brave and sassy self.
One common theme is the clash of different worlds. Twilight has its own supernatural realm and Bones is more about crime and forensics. So when they cross over, there's often a theme of how these two different worlds interact.
One common theme is the clash of investigation styles. The NCIS team has its own way of doing things, and the Bones team has theirs. So, in fanfiction, this can lead to interesting conflicts and resolutions. For example, Gibbs' no - nonsense approach might contrast with Brennan's more scientific and sometimes overly - rational thinking.
One great Bones crossover fanfiction is the one where Bones characters cross over with the characters from 'CSI'. It creates an interesting dynamic as the forensic methods of both shows are compared and contrasted. The different personalities from each show interact in unique ways, like Temperance Brennan's scientific approach clashing and also meshing with the CSI team's style.
One challenge is maintaining the tone of 'the lovely bones'. It has a very specific, somewhat melancholy and ethereal tone. When crossing it over with another story, it can be hard to keep that while also incorporating the new elements. Another is making the crossover believable. The two worlds or stories need to blend in a way that makes sense to the readers.
The plot could revolve around a missing person who has a connection to both the world of Warehouse 13 and Bones. Maybe the missing person was researching an artifact for Warehouse 13 and also had some sort of relationship with a case that Bones was working on. The two teams would then have to combine their resources. The Warehouse 13 agents could look into any possible artifact - related reasons for the disappearance, like if the person was targeted because they knew too much about a dangerous item. The Bones team could search for any physical evidence at the person's last known locations.
In a crossover fanfiction of Alita: Battle Angel, Alita could find herself in the world of Blade Runner. She'd be amazed by the neon-lit cityscapes and the complex web of human - and non - human - relationships. As she wanders the rain - soaked streets, she meets Deckard. Alita's combat skills would astound him, and together they might uncover a conspiracy that links the two universes, perhaps a powerful corporation is using replicant technology and Alita's cyborg technology for some evil purpose.
One idea could be that Brennan and Castle team up to solve a crime that has elements related to both their areas of expertise. Maybe it involves a historical skeleton discovery at a crime scene Castle is investigating.