I'm not sure specifically as I haven't read it. But they could be astronauts, space explorers, or even beings from other planets. Maybe there's a brave captain leading a crew on a journey through the cosmic sky.
In a 'cosmic sky fanfic', the main characters could be diverse. There might be a group of intergalactic travelers who are on a mission to find a new home in the vastness of the cosmic sky. There could be a wise old star - being who acts as a guide for them. Additionally, there may be a character who is a hybrid of human and some other cosmic entity, and this character has unique powers that are related to the cosmic sky, such as the ability to control the energy of the stars or communicate with celestial bodies.
Perhaps there are astronauts as the main characters. They are exploring the cosmic sky and fall in love during their journey among the stars.
Well, 'cosmic sky fanfic' might center around the beauty and mystery of the sky in a cosmic context. Maybe it has stories of astronauts who look out at the cosmic sky and experience extraordinary things. It could also include elements of science fiction, such as new forms of life that exist in the regions near the sky as seen from a cosmic perspective. For example, there could be tales of alien races that live among the stars and how they interact with our view of the sky.
There could also be antagonists in the fanfic. For example, the Trix, a group of witches who are always causing trouble for Bloom and her friends. They could be the main source of conflict in the story, constantly trying to thwart Bloom Sky's plans and steal their powers.
Since I don't know the specific 'black sky fanfic', I can't say who the main characters are. They could be original characters created by the fanfic author, or they might be characters from an existing franchise that the fanfic is based on.
Naruto would surely be one of the main characters. He could be the one who bridges the gap between the regular ninja world and the sky ninja. Sasuke might also be involved, perhaps having some sort of rivalry with a sky ninja who has similar power levels. Sakura could play a role in healing the injured during the interactions between the two groups.
Based on the title, it seems that Bloom and Sky are the main characters. They are likely the ones involved in the kiss and around whom the fanfic's story revolves.
The celestial sky dragon itself is surely one of the main characters. There may also be some other important characters like a wizard or a fairy who might interact with the dragon in different ways.
Obviously, Harry Potter is one of the main characters. He brings his knowledge of the wizarding world, his Gryffindor courage, and his skills in magic like spells and potions. Sky Arcoblano is the other key character. He has his own set of characteristics which could include unique powers or a different cultural background from his own world that adds an interesting element to the story.
Obviously, the original character (OC) is one of the main characters. But there might also be other characters from Warren's 'sky high' universe that play important roles, like teachers or powerful students.
Typically, in Gundam Wing fanfic, the main characters would likely include Heero Yuy, Duo Maxwell, Trowa Barton, Quatre Raberba Winner, and Wufei Chang. But without reading the specific 'As I Touch the Sky' fanfic, it's hard to be certain if there are any new or modified versions of these characters.