A fanfiction like this might explore how Harry's experiences in the wizarding war have made him a more complex and battle - hardened character. He could bring a new perspective to the Avengers, perhaps teaching them about the importance of unity in the face of great evil, which he learned from his time at Hogwarts and in the fight against Voldemort.
He might start off being a bit of an outsider. The Avengers are used to a certain type of hero, and Harry with his magic would be very different. But he could win them over with his courage and loyalty, much like he did with his friends at Hogwarts.
One possible story could be that after the war, Harry suffers from paraplegia due to some dark magic he endured during the final battle. Ginny stays by his side, being his strength. She helps him through the difficult process of physical therapy. Their love becomes even deeper as they face this new challenge together.
Harry could become an Auror, as he's always been good at fighting dark forces. Ginny, on the other hand, might continue her career in Quidditch. They would support each other's choices. Harry would cheer for Ginny at her matches, and Ginny would be proud of Harry for his work in keeping the wizarding world safe.
He might become very self - reliant. Since he has no one to depend on, he learns to take care of himself in every aspect, like finding his own place to live and getting food. He could also start to study magic more independently, exploring areas that were previously forbidden or not well - known.
The new villains in 'Avengers After Infinity War Fanfiction' could include a group of super - powered individuals who were once under Thanos' control but now have their own agenda. They might have powers that are a combination of the Infinity Stone's energy and their own genetic mutations. They could be led by a charismatic figure who has a vision of a new world order, one that is not friendly to the Avengers or the people of Earth. Additionally, there could be a cosmic entity that was awakened by the events of Infinity War and sees Earth as a threat to the balance of the universe.
Some fanfictions might depict them as having a more adventurous post - war life. They could be involved in rebuilding the wizarding world in a more hands - on way. Harry might use his fame and Ginny her popularity among the younger wizards to bring about positive changes. Their relationship would be based on mutual respect and a shared goal of making the wizarding world a better place.
Harry might become more at peace. After all the battles and losses, he could focus on the positive aspects of life. Luna, on the other hand, could become more confident in sharing her ideas. She no longer has to be in the shadow of the war and can be more outspoken.
They could become very close friends. After the war, they both have a shared understanding of the trauma and changes they've been through. They might support each other in rebuilding their lives at Hogwarts or in the wizarding world in general.
One idea could be the remaining Avengers finding a way to reverse the Snap in a completely unexpected way, like traveling to a different dimension where Thanos never got the Stones. Another could be the rise of new heroes among the survivors, who have unique powers that can help in the fight against Thanos' legacy. And perhaps some of the snapped heroes are actually alive in a sort of pocket universe and the Avengers have to figure out how to bring them back from there.