It could be an original omega mutant character created specifically for the fanfic. This character might have abilities that are a blend of Naruto - like ninja skills and mutant - like powers.
There might also be a villain who is against the omega mutants. This villain could be a power - hungry ninja who sees the mutants as a threat to his own power and status in the ninja world. His actions against the mutants drive much of the conflict in the fanfic.
Well, Naruto is the most obvious main character. He would be exploring the boundaries of his powers in this fanfiction world. But it's possible that some mutant - like characters from the Naruto universe, like Gaara with his sand - controlling abilities that could be seen as mutant - like, could also be main characters. Additionally, new characters created specifically for this fanfiction that bridge the gap between Naruto's world and the mutant concept could be main characters as well.
Itachi can be a very interesting character in Naruto omega mutant fanfiction. His past actions and his own powerful abilities can contrast and interact with Naruto's omega mutant nature. Jiraiya is another one. He could be the one who first discovers Naruto's mutant abilities and helps him start on the path of understanding and mastering them. Then there are the Akatsuki members, whose motives and actions can be affected by Naruto's new omega mutant status.
In this type of fanfiction, characters like Itachi might be very popular. His already - complex character can be made even more so with omega - level mutant powers. He could have the power to manipulate shadows in a more extreme way, similar to a mutant ability. Also, Rock Lee could be popular if he is given mutant - like super strength and speed that take his taijutsu to a whole new level.
Hermione could be a great main character. Her intelligence combined with omega - level mutant intelligence or some kind of knowledge - based power like eidetic memory as a mutant ability would be really interesting. She could use her mutant ability to solve magical problems in new ways.
One interesting plotline could be the discovery of new powers among the omega mutants in the Naruto universe. For example, they might have unique jutsu related to their mutant abilities.
Often, original characters created by the fanfic authors themselves become popular. These are the ones with really unique omega level powers and interesting backstories. For example, a character who can control all forms of energy and has a tragic past of being experimented on by an evil organization.
Some original omega - level mutants created specifically for the fanfiction can also become popular. For example, an omega - level mutant with the power to manipulate time might be a really cool and popular character. Their interactions with the SI character and how they use their power to change or protect the mutant world can make them stand out.
It's hard to say for sure without reading it, but it could include Naruto himself. Maybe he has a different role in this fanfiction, like being involved in the omega - related events in a special way.
In 'oc omega mutant fanfic', the theme of transformation is quite common. The omega mutants usually start off in a rather weak or oppressed state, but through various experiences and character development, they transform into stronger, more confident individuals. It's like a journey from being an outcast to becoming a hero or a respected figure in their own right. For example, in some fics, an omega mutant might initially be afraid to use their powers, but as the story progresses, they learn to master them and use them for good.
Sometimes there could be an older, wiser dog that acts as a mentor to the puppies. This character could offer advice and guidance to the alpha and omega puppies, especially when they face difficult situations like dealing with a predator or finding a new place to live.