First, you need to be really familiar with both universes involved in the crossover. For Stargate, know the different gates, the Goa'uld, and the various teams. Then, come up with an interesting premise. Maybe it's a new enemy that can only be defeated by the combined forces of the two universes in your crossover. Keep the characters true to their original personalities.
A Stargate and Battlestar Galactica crossover can also be amazing. Picture the Stargate teams dealing with the Cylons. The fanfiction often explores how the military strategies from both franchises would clash or blend. It usually has a lot of action - packed scenes as well as some deep character - driven moments.
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.
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.
The Ministry of Magic would probably oppose it. They are always concerned about maintaining the secrecy of the wizarding world and a stargate could potentially expose it to non - magical beings or lead to unwanted magical interference from other realms.
In the original Stargate series, Alteran knowledge was more of a background element. However, in 'Stargate Alteran Knowledge Crossover Fanfiction', it becomes the central focus. The fanfiction might introduce crossovers with other fictional universes or concepts, which is not a part of the original series. Also, the fanfiction can play around with the Alteran knowledge timeline, perhaps showing how it could have been used differently in different eras compared to what was shown in the original.
In Stargate Atlantis fanfiction, if John Hurt is included, he might bring a different dynamic to the team. His character could have unique abilities or a backstory that ties into the existing lore of the Stargate universe. For instance, he could be related to one of the ancient races in a way that no one expected. This could lead to all sorts of adventures and plot twists as the characters in Atlantis interact with him.
John Hurt can be significant in Stargate Atlantis fanfiction as he can be used to create new story arcs. His acting skills allow for complex characterizations that can fit well into the sci - fi world of Stargate Atlantis.
One idea could be to have the characters from RWBY travel through a stargate to the Pegasus Galaxy where Stargate Atlantis is located. They could encounter the Wraith and have to use their unique abilities from Remnant to fight them. For example, Ruby's speed and Crescent Rose could be very useful in combat against the Wraith.
One common theme is the exploration of forbidden love. Since it's slash fanfiction, often the relationships are between characters that might not be expected to be together in the original series, so there's that element of the relationship being against the norm.