One of the main antagonists could be the Kingpin. He has a long - standing enmity with Spider - Man and would surely not like Peter Parker being in a position of power at Alchemax. He could try to undermine Peter's leadership through various illegal and underhanded means, like bribing employees or spreading false rumors. Also, Electro might be an antagonist. He could target Alchemax for its power sources, which he could use to increase his own electrical powers and cause chaos in the city.
The Green Goblin could be a main antagonist. He might see Peter's control of Alchemax as a threat to his own criminal empire and try to take over the company or destroy it. Another could be Doctor Octopus. With his brilliant mind, he may want to use Alchemax's resources for his own mad experiments.
In the 'Peter Parker CEO of Alchemax fanfiction', there could be a storyline where Peter is trying to make Alchemax more inclusive. He might start initiatives to hire more minorities and women in scientific fields. He also could be using the company's influence to support local communities. On the other hand, he may face challenges from competitors who see his new - age ideas as a threat to their traditional business models. And of course, there will always be the lurking threat of super - villains who target Alchemax either for its technology or to get back at Peter Parker.
The Green Goblin could be a main antagonist. He's known for causing chaos in New York City, and a building collapse would be right up his alley. He could be targeting the building for some strategic reason, like trying to get to Peter Parker or to create general mayhem.
Maybe it's a group of intergalactic criminals who are after the power that Peter Parker has as a 'child of the universe'. They could be stealing artifacts from different planets to gain more power and they see Peter as the ultimate source of power that they need to complete their collection.
Peter Parker's interactions with Alchemax in fanfiction can be complex. For example, he could be in a situation where he has to work with Alchemax to save the city from a greater threat, even though he doesn't trust the company. Or he might be trying to expose Alchemax's illegal activities by getting close to key employees. There are also stories where Peter's alter - ego as Spider - Man is targeted by Alchemax for their own purposes, leading to a cat - and - mouse game between them.
Venom could be a formidable antagonist. He might be attracted to the chaos and different powers at Monster High. He could start infecting some of the students, turning them into his minions. Additionally, a group of anti - monster humans from Peter's world could find out about Monster High and decide to invade it. They see the monsters as a threat and want to 'cleanse' the school, which would put Peter in a difficult position as he has to protect his new friends from his own kind.
The main antagonists could be the official Avengers themselves. Since Peter Parker has joined the rogue Avengers, the main Avengers group might see them as a threat to the order they are trying to maintain. They could try to stop the rogue Avengers from achieving their goals, which would put them in direct conflict with Peter and his new allies.
A new and original antagonist could be a rogue psychologist who has developed a powerful hypnosis technique. This character might be jealous of Peter's abilities and want to use hypnosis to take over his mind and use his powers for their own gain. Or it could be a secret organization that wants to use Peter as a weapon, and they use hypnosis as a means of control.
One interesting 'Peter Parker Alchemax' fanfiction could be about Peter using Alchemax technology to enhance his Spider - Man suit. For example, he might discover a new type of web fluid formula at Alchemax that gives his webs special properties like increased strength or the ability to conduct electricity. Another could involve Peter working undercover at Alchemax to uncover some corporate evil while still maintaining his superhero identity. There are also fanfictions where Alchemax tries to clone Spider - Man using their advanced genetic research facilities.
Often, other symbiotes can be the main antagonists. For instance, Venom himself might see Anti - Venom (Peter) as a threat and constantly try to attack him. Venom could be jealous of the power that Anti - Venom has or simply view Peter as an enemy because of the different nature of their symbiotic relationships.
The Green Goblin is often a common antagonist. His chaotic nature and vendetta against Spider - Man would still be a major threat even if Peter is reborn. He might come up with new and more devious plans to take down Spider - Man.