A common theme is growth. Nebula grows from a damaged and somewhat cold character to someone who can love and be loved. Tony also grows in his understanding of family and responsibility. There is also the theme of second chances. They are both given a second chance at life and at having a family through their adoption - like relationship.
One common theme is redemption. Tony may be seeking redemption for leaving Nebula in space, and Nebula herself may be on a path of self - redemption. Another theme is family. They create a new family unit out of their shared experiences and traumas.
One common theme is survival. Given their situation in space, a lot of fanfictions explore how they survive together. For instance, they might have to find ways to get food and water on that desolate planet.
One common theme is survival. Given their experiences in space and facing tough situations, many fanfictions focus on how they rely on each other to stay alive.
One popular 'Tony adopts Nebula' fanfiction might be 'A New Family' where Tony takes Nebula under his wing after their shared experiences. He helps her adjust to life on Earth, and it shows their growing bond as they both heal from their traumas.
One common theme is family. Since it's about adoption, the idea of creating a new family bond between Tony and Harry is central. They learn to support and love each other like family.
One common theme is redemption. Loki often has a troubled past, and in these fanfictions, his adoption by Tony becomes a path towards redeeming himself.
Healing is another common theme. Both characters usually have their own emotional wounds. In these fanfics, through their relationship of adoption, they help each other heal. For example, Bucky's stability can help Tony deal with his insecurities, and Tony's intelligence and humor can help Bucky come to terms with his past.
The theme of friendship also exists. Naruto makes friends with characters he meets in the nebula - related scenarios. These friendships are often tested through various challenges, similar to how his friendships in the Naruto anime are put to the test, but in a more out - of - this - world setting.
Another theme is adventure. They are both characters associated with space and exploration. So, in fanfictions, they often embark on exciting adventures together, like exploring uncharted planets or facing new and strange alien species. It's really exciting to read about their exploits in these fictional stories.
Adventure is a common theme. Harry is often on a journey exploring the nebula, facing unknown dangers. Another theme is discovery, like finding new species or magic in the nebula.
One common theme is friendship. They both have complex personalities, and fanfictions often explore how they become friends and support each other.