A good antagonist could be a character from the 'Resident Evil' universe, like Albert Wesker. His superhuman abilities and evil plans for global domination would pose a huge threat to Alex Rider. Alex would have to use his wits and skills to stop Wesker's bio - terrorist plans.
You could also do a crossover with 'Sherlock Holmes'. Alex Rider is on a case that Holmes has also been investigating. Alex's modern - day espionage skills and Holmes' deductive reasoning could combine in interesting ways. Alex might be able to provide the physical evidence that Holmes deduces from, and Holmes could help Alex see the bigger picture of the mystery.
One idea could be that Alex Rider is sent on a mission that overlaps with a CHERUB operation. They initially suspect each other as spies from different agencies but then realize they can work together. Maybe they have to infiltrate a high - security facility that is involved in some sort of illegal arms trading.
One possibility could be that Alex Rider is on an undercover mission that somehow intersects with an NCIS case. Maybe he's tracking down a group involved in international espionage and they turn out to be linked to a crime on U.S. soil that NCIS is also investigating. For example, a terrorist organization that is smuggling weapons and using the sea routes which is NCIS' area of expertise. Alex could bring his unique skills in combat and infiltration, while the NCIS team offers their forensic and military investigation knowledge.
One idea could be an Alex Rider crossover with James Bond. Alex could be recruited by MI6 to assist Bond on a mission. They would bring their unique skills together, with Alex's youth and agility complementing Bond's experience and suave charm.
In a crossover fanfiction, Alex Rider could bring his knowledge of various scientific and technological devices to the Avengers. He might help Tony Stark improve some of his suits or help Bruce Banner with some research. Together, they could face a threat that is specifically targeting the Avengers' weaknesses. For instance, a villain has developed a way to disrupt the Hulk's transformation and disable Iron Man's suit, and Alex's outside - the - box thinking helps them find solutions.
The uniqueness of Alex Rider Crossover Cherub fanfiction lies in the combination of two different espionage - themed fictional worlds. Each has its own set of characters with distinct personalities and skills. When they cross over, it creates new and unexpected storylines.
Well, I've read some where they start off as rivals. In this type of Alex Rider Crossover Cherub fanfiction, the two groups initially compete for the same objective, like getting hold of a crucial piece of intelligence. But as the story progresses, they realize they need to work together. It's a great plot device that can lead to some really exciting action scenes and character development.
You can start by looking on fanfiction.net. It has a large collection of fan - made stories, including many crossovers involving Alex Mercer. Archive of Our Own (AO3) is also a great place. It has a well - organized tagging system, so you can easily search for Prototype and crossover related stories. Another option is Wattpad, which has a growing community of fanfiction writers, and you might find some unique takes on the Alex Mercer crossover there.
One idea could be a crossover with the Resident Evil universe. Alex Mercer could find himself in Raccoon City during the zombie outbreak. He might use his powers to either fight the zombies or try to figure out what's causing the outbreak. Another idea is a crossover with the X - Men. Mercer's shape - shifting abilities could be an interesting contrast to the mutants' powers, and there could be a conflict or an alliance depending on the story's direction. A third idea is a crossover with the God of War series. Imagine Mercer in the world of Greek mythology, facing off against gods and monsters.