Doctor Strange could also be a main character. Since he had a big role in Infinity War with his visions of the future, in the aftermath he could be using his magic to try and find a way to fix the damage. He might be exploring different dimensions to find answers or artifacts that could help. He could also be teaching some of the other Avengers basic magic for self - defense.
Captain America could be the main character. He's always been a leader, and in the aftermath, he could be the one trying to hold the remaining Avengers together. He would be dealing with his own sense of loss and responsibility. He might also be trying to figure out how to prevent future disasters like Infinity War.
Nebula could be the main character. She has her own story of survival and revenge. In the aftermath, she could be on a mission to make sure Thanos' actions never happen again. She might be teaming up with the Avengers, sharing her knowledge of Thanos' technology and weaknesses. Also, her relationship with the other characters, like Tony Stark, could be further explored.
Wanda Maximoff could also be the main character. After losing Vision, she could be on a rampage. But then she realizes that she needs to control her powers and use them for the greater good. She could be a key player in trying to bring back the vanished ones and fighting any new threats that emerged after Infinity War.
A plot might also revolve around the villains. Some villains might see the chaos as an opportunity to take over. The Avengers would then have to deal with new threats while still recovering from the events of Infinity War. The fanfic could show how they come up with new strategies and alliances to face these challenges.
In the 'Avengers Infinity War Aftermath Novel', one of the main events is dealing with the aftermath of Thanos' snap. Survivors are left in a state of shock and despair. They also start to figure out how to move forward and if there's any way to reverse what has been done.
Some of the key characters are the remaining Avengers. Iron Man, Captain America, and Thor are still important figures in the novel as they try to deal with the situation. Also, characters like Black Widow who are trying to hold things together on Earth.
Another plot could focus on Thor. After losing so much in Infinity War, he might become a bit of a recluse. But then he realizes that he has a responsibility to the remaining Asgardians and the universe. So he starts to gather the remaining heroes and form a new plan to fight against the consequences of Thanos' snap.
A third storyline could be about the villains who survived or emerged after Infinity War. Maybe some of them see an opportunity to take over in the power vacuum left by Thanos. The fanfic could explore how the heroes have to deal with new threats while still reeling from the events of Infinity War.
It could be a new villain that emerges from the power vacuum left by Thanos. Maybe one of his underlings decides to step up and continue his tyrannical ways.
Most likely it would still be Thanos. Since he was the main villain in Infinity War and his actions were the cause of so much destruction, it makes sense that he would continue to be the main adversary in the sequel.
Nebula is an interesting choice as well. She has a complex relationship with Thanos and has been through a lot. In the aftermath, she could be a key figure in trying to find a way to undo what Thanos has done. Also, her unique skills and knowledge of different parts of the universe could play an important role in the fanfic.
Well, Naruto characters have unique abilities. For example, Naruto's shadow clones could be used for various strategies. Sasuke's Sharingan could detect hidden threats. They could join the Avengers to fight against Thanos. Maybe Naruto's Rasengan combined with Iron Man's repulsor technology could create a super - powerful attack.