A possible fanfiction could revolve around a joint mission. The races from Babylon 5 and the teams in the Stargate universe come together to face a common threat. Maybe an ancient evil that has the power to destroy both their worlds. They would have to combine their knowledge and resources, like the Psi Corps abilities from Babylon 5 and the Ancient technology in Stargate.
In a Stargate Babylon 5 crossover fanfiction, a possible plot could revolve around a mysterious energy source. This energy source could be something that is of great interest to both universes. Scientists from Stargate and Babylon 5 could team up to study it. However, different factions within each universe may have different ideas about how to use this energy. This could lead to internal conflicts as well as conflicts between the two universes. It would be a story full of political intrigue, scientific discovery, and adventure.
One challenge is getting the lore right for both universes. Each has its own complex set of rules, technologies, and species. For example, the Babylon 5 universe has the Vorlons and the Shadows, and the Stargate universe has the Goa'uld. Keeping all these elements consistent is difficult.
One idea could be that a Sentinel's enhanced senses are used to detect a hidden Goa'uld base that the Stargate team has been searching for. The Sentinel could sense the unique energy signatures or the presence of the symbiotes in a way the normal technology couldn't. Another idea is to have a Sentinel character be accidentally transported through the Stargate to a different planet. There, they have to use their Sentinel abilities to survive and team up with the Stargate team members who are also on a mission there.
John Sheridan from Babylon 5 and Jack O'Neill from Stargate could make an interesting pairing. Sheridan is a strong leader and diplomat, while O'Neill is a military man with a sense of humor. They could learn a lot from each other. Another could be Delenn from Babylon 5 and Samantha Carter from Stargate. Both are intelligent women with different areas of expertise. Carter in science and technology, and Delenn with her spiritual and political knowledge.
Well, in Roswell Stargate crossover fanfiction, there might be a plot where the characters from Roswell get involved in Stargate missions. Imagine the Roswell gang having to deal with the Goa'uld or the Replicators. It could also be about how the technology from Stargate affects the lives of the Roswell aliens. For instance, the Stargate could be a way for them to find a cure for their alien - related problems or a means to enhance their powers.
One idea could be that the Spartans from Halo are sent through a Stargate to an unknown planet in the Stargate universe. They have to team up with the SG teams to fight off a common enemy like the Flood that has somehow spread to that planet. Another could be a scenario where the technology from both universes is combined. For example, the Covenant's energy shields are integrated with the Stargate's shield technology.
One interesting idea could be the interaction between the different alien species from both universes. For example, seeing how Vulcans from Star Trek would interact with the Minbari from Babylon 5. Maybe they would exchange knowledge on logic and philosophy.
One idea could be the Stargate teams finding a derelict Battlestar and trying to figure out its technology. They might encounter some of the Cylon technology which could pose a new threat or a source of new knowledge for them.
One idea could be a crossover with Star Trek. Imagine the Stargate team traveling through a wormhole and ending up in the Star Trek universe. They could interact with the Federation, learn about their technology like the warp drive, and perhaps even help solve a crisis together.
One idea could be to cross Stargate Universe with Stargate SG - 1. Maybe the Destiny crew discovers an ancient technology that was originally developed by the SG - 1 team on Earth. This could lead to a joint mission where both crews have to work together to unlock the secrets of the technology and use it to save both their ships and Earth from a new threat.