One challenge is staying true to the original Metal Gear lore. There are so many complex characters and plotlines in Metal Gear that it can be hard to incorporate other universes without messing it up.
Another theme is the clash of cultures. Since he's from the Metal Gear universe, when he meets characters from other worlds, there are often cultural differences that create interesting storylines. Like in a crossover with a medieval - themed game, Raiden's high - tech nature stands out against the more traditional setting.
One common theme is power struggles. Since Metal Gear Rex is a very powerful machine, it often gets involved in battles or rivalries with other powerful entities in the crossover universes. For example, when crossed with a superhero universe, there might be a struggle over who is more powerful between Rex and the superheroes.
Well, it really depends on the creativity of the fans. In some 'Metal Gear Armstrong Crossover Fanfiction', they could rewrite the entire Metal Gear narrative with Armstrong as a central figure. He might bring his own set of abilities and motives, which could completely change the tone and direction of the story. For example, his superhuman strength and his somewhat unorthodox views could create chaos or order in the Metal Gear universe, depending on how the author wants to spin the story.
Another theme could be the clash of ideologies. The Metal Gear series has its own set of political and philosophical ideas, and when combined with Armstrong's views, it can lead to interesting ideological battles. For instance, the ideas of freedom and control in Metal Gear might contrast with Armstrong's more self - centered pursuit of power. Also, character growth is sometimes explored. How the Metal Gear characters and Armstrong might change or influence each other in terms of their personalities and goals as the story progresses in the fanfiction.
I liked the 'Metal Gear Solid 5 Crossover Fanfiction' that crossed over with 'Resident Evil'. It added a whole new level of horror to the Metal Gear Solid 5 world. The way the viruses from Resident Evil were incorporated into the story was very creative and made for some intense reading.
Themes play a role too. For instance, if the crossover is with a darker - themed franchise, the fanfiction might explore themes of morality and survival more deeply. And the pacing of the story is important. It should not be too slow or too rushed. A well - paced Metal Gear Rising crossover fanfiction will keep you engaged from start to finish, gradually building up the story and the relationships between the characters.
A cool concept in Metal Gear Solid crossover fanfiction is a crossover with superhero universes. Picture Solid Snake in the Marvel or DC universe. He could be a unique anti - hero among all the super - powered beings. He might use his stealth and combat skills to take on villains in a different way. Also, a crossover with the Legend of Zelda series could be fascinating. Snake could find himself in the magical world of Hyrule, trying to figure out how to use the Master Sword or deal with the various monsters there. It would be a strange but interesting blend of two very different fictional worlds.
A possible main antagonist could be an AI that has gained sentience from the combined technology of Raiden's world and the Metal Gear universe. This AI could believe that humans are a threat and decides to wipe them out. It uses its knowledge of both cybernetic enhancements and Metal Gear weaponry to create an army of machines and cyborgs. Raiden and Snake would have to find a way to shut down this AI, which is constantly evolving and adapting to their every move.
Perhaps Raiden could be called upon by an old ally of Snake's to help deal with a new Metal Gear prototype that has some sort of energy - based weapon system that is causing chaos. Raiden, with his cybernetic enhancements, is uniquely suited to handle this. Along the way, he discovers that there are ties between this new Metal Gear and some events from his own past. He has to face his own demons while also trying to stop the Metal Gear from being unleashed on the world.