Who could be the main characters in 'a captain's promise fanfiction' besides the captain?

A scientist could be a main character. They would be interested in studying Captain Olimar, trying to understand his biology and the technology he uses. Maybe a child as well. Children are often curious and open - minded, so they could form a quick bond with Olimar, teaching him about simple human things like toys and snacks.

Urahara Kisuke would be a great addition. His mysterious nature and vast knowledge could either help or hinder Naruto. Yoruichi could also be a main character. Her cat - like abilities and combat skills would make for some exciting interactions with Naruto. She could teach Naruto some new moves or they could team up against a common enemy.

Well, obviously Captain Darko is a main character. He's the central figure around which the stories revolve. There might also be his trusty first mate, someone who has been with him through thick and thin. This character could provide support and sometimes comic relief.

Obviously, Percy is the main character as he is the captain. But depending on the type of fanfiction, there could be other important characters. For example, if he's a sports captain, his teammates would be significant. They could have different personalities and skills that interact with Percy's leadership. If he's a ship captain, his crewmates, like the navigator or the first mate, would play important roles in the story.

Obviously, Captain Hook's daughter would be a main character. And Captain Hook himself would play a significant role as well.

The main characters are Naruto and Samui. Naruto's journey to become a great ninja and his experiences in the ninja world provide a rich backdrop. Samui, with her own backstory and her role in her own village, adds another layer. Fanfictions often explore how their paths cross and the relationships and adventures that unfold as a result.

One idea could be exploring the backstory of the captain before the promise was made. Maybe there was a tragic event in their past that led them to make such a solemn vow. Another could be a situation where the captain has to break the promise to save their crew, and then deal with the moral and emotional consequences.

The Night King could be a great antagonist. His army of the dead and his own powerful magic would pose a huge threat to Captain America. Cap's used to fighting human foes, but the Night King is something entirely different.

In some Captain's Hart fanfic, there could be antagonists that oppose Captain Hart. These characters are crucial as they create conflict and drive the plot forward. They could be rival captains or evil entities from other galaxies.

It could be a rogue Amazon who disagrees with the idea of an outsider like Captain America being on Themyscira. She might see him as a threat to their way of life and try to drive him out, or even worse, harm him.