One popular plot twist could be that Venom was actually a creation of an enemy of the Avengers, designed to infiltrate and destroy the team from within. Another might be that the Venom symbiote had a mind of its own and was trying to take over the world, using the Avengers as pawns.
Well, in 2018 Avengers fanfiction, a really interesting plot twist was that the Venom symbiote was actually a part of an ancient prophecy. The Avengers initially thought it was just a dangerous alien entity. But as the story unfolds, they discover that it has a deeper connection to the fate of the Earth and the universe. Another plot twist could be that Venom has the ability to absorb the powers of the Avengers it comes in contact with. So, as it battles different members of the team, it becomes more and more powerful, making it an even greater threat.
Maybe in the fanfiction, the Avengers initially think Peter Stark is just a regular kid related to Tony Stark, but then they find out he has the ability to time - travel. This would completely shift the story as they would have to deal with the implications of time manipulation and how it affects their missions and relationships.
A really interesting plot twist is when a Jedi is able to turn Venom to the light side in some fanfictions. It goes against the usual dark nature of Venom and makes for a really unique story where the Jedi and Venom then fight together against the Sith.
One popular plot twist is when one of them is thought to be a traitor. For instance, Natasha might be framed as working for the enemy. Steve would then be conflicted between his loyalty to her and his duty to the Avengers. This creates a lot of tension and drama in the fanfiction.
One interesting plot twist could be that Venom starts to have memories of Peter Parker's life as Spider - Man. This would create a strange dynamic where Venom understands Spider - Man's motives on a deeper level and might even start to protect the things Spider - Man cares about. For example, Venom could find itself saving Mary Jane from a random mugger because it has a new - found sense of connection to Spider - Man's world.
One exciting plot twist could be Venom actually teaming up with Spider - Man to fight a greater evil. Maybe a new super - villain emerges that is too powerful for either of them alone. Another could be that Venom's host has a change of heart and wants to be a hero, leading to a very different dynamic between him and Spider - Man. And sometimes, there might be a plot twist where Spider - Man is forced to take on some of Venom's powers temporarily, which completely changes the way he approaches battles.
A common plot twist is that Kid Tony turns out to be a key to solving a major problem the Avengers are facing. For example, in one fanfic, a powerful enemy has a shield that can't be broken, but Kid Tony figures out a way to disable it with his unique understanding of energy fields.
In some fanfictions, a plot twist could be that Ghost Rider is actually a key to unlocking an ancient power that the Avengers need to defeat a new, extremely powerful enemy. This changes the whole dynamic as the Avengers have to protect and work with Ghost Rider in a different way.
In some Batman vs Avengers fanfiction, a great plot twist is when Batman manages to hack into the Avengers' communication system and makes them fight among themselves. He then uses the chaos to his advantage. Another cool twist is that there's a greater threat looming, and Batman and the Avengers have to put aside their differences and work together. But as they do, they discover that one of the Avengers has been replaced by a shape - shifter, and Batman has to figure out who it is before it's too late. There could also be a plot twist where Batman uses a device that actually amplifies his own strength and skills to the point where he can match the Avengers' superpowers, at least temporarily.
In some fanfics, a great plot twist is when Ghost Rider turns out to be the key to defeating an enemy that the Avengers thought was unbeatable. His hellish powers were the one thing that could counter the enemy's invulnerability.
Well, a common plot twist is when Kid Loki turns out to be the only one who can understand an ancient prophecy that involves the Avengers. This throws the whole team into chaos as they have to rely on him to figure out their next moves. Another plot twist could be that Kid Loki's mischievous acts were actually a way to test the Avengers' loyalty and strength, and in the end, he unites them in a way no one expected. Also, he might be able to transform into a powerful being that the Avengers initially thought was a different entity, and this revelation changes their battle plans entirely.