There may also be side characters such as the girl's friends or family members. Her friends might be other horse girls, and they could go on adventures together, or her family could be either supportive or skeptical of her horse - related activities, adding more depth to the story.
The horse is also a main character in a way. It has its own personality. In some graphic novels, the horse might be a wild mustang that the girl befriends and tries to tame. The horse could be stubborn at first but gradually forms a deep bond with the girl, like in stories where the horse helps the girl overcome her fears or achieve her goals.
Since I don't know the exact 'horse girl story', it's hard to say for sure. But most likely, the main character would be the girl who has a connection with horses. There might also be the horses themselves as important characters.
Since I'm not familiar with the 'on a pale horse graphic novel', it's hard to say. However, it might have a protagonist who is somehow associated with the pale horse, like a person who discovers the horse or is chosen by it. There could also be an antagonist who opposes the main character's journey or purpose related to the horse.
The girl and the horse are the main characters. The girl could be of any age, with her own personality, dreams, and fears related to the horse. The horse, on the other hand, has its own characteristics like its breed, color, and temperament that play a role in the story.
There are soldiers. They play important roles as they interact with the horse during the war.
There's also Sydney Savage. She's known for her combat skills and fearless attitude. Another important character is Natalia Kassle, who brings her own set of skills and knowledge to the Danger Girl team.
In 'Ms. Marvel', the main character is Kamala Khan. She's a normal girl who idolizes superheroes and then suddenly gains shape - shifting powers. In 'Wonder Woman' graphic novels, of course, it's Diana Prince. She's an Amazon warrior princess with superhuman strength, speed, and the ability to fly. In 'Squirrel Girl', Doreen Green is the lead. She has the ability to communicate with squirrels and has squirrel - like powers, which she uses to fight crime in a really fun and unique way.
Since I haven't read this particular 'dark horse aliens graphic novel', it's hard to say for sure. However, common main characters in such stories could be a brave military leader who has to defend Earth against the aliens, a curious scientist who wants to study the aliens rather than fight them, or a young person with some special ability that becomes important in the encounter with the aliens.
Liz Sherman is another important character. She has pyrokinetic abilities, which means she can control fire. She has a complex personality and a troubled past. Her relationship with Hellboy is also an important aspect of the story, as they often team up to fight against the forces of evil in the 'Dark Horse Hellboy Graphic Novel'.
Since I don't know the exact story, it could be the horse girl herself as one of the main characters. And perhaps the person she has fallen in love with, who could be a stable boy, a nobleman (if it's a story with a class - based conflict), or just an ordinary person from a different background.
The main characters are obviously the young girl and the horse. The girl could be a tomboyish character, full of energy and a love for animals. The horse could be a majestic stallion or a gentle mare.