I don't know for sure as we haven't been given much information about the 'dark moon story'. It could be a lone adventurer as the main character.
In the story of Transformers Dark of the Moon, Sam Witwicky is a central human character. He has been involved with the Transformers for a while. On the Autobot side, Optimus Prime is crucial. He is the strong and noble leader of the Autobots. Bumblebee is Sam's friend and a very popular Autobot. Megatron, on the other hand, is the fearsome leader of the Decepticons. He is always plotting and trying to gain power. There are also other Autobots and Decepticons that play important roles in the battles and the overall story.
I don't know the exact main characters in the 'Dark of the Moon Novel' since I haven't read it. But they could be the typical heroes like a brave young man or woman, or an old wise figure who guides the others.
In the 'Transformers Dark Side of the Moon Story', the main characters include Optimus Prime, who is the brave leader of the Autobots. Sentinel Prime, who has a complex role in the story. Megatron, the menacing leader of the Decepticons. And Bumblebee, who is loved for his cute yet brave nature. There are also other Autobots and Decepticons that contribute to the story, but these are some of the most prominent ones.
I don't know specifically as I haven't read the 'dark moon era novel'. But they could be survivors, heroes, or villains in the context of the story set in this era.
Since it's a junior novel, there might be a group of kids as the main characters. They could be friends who support each other through the events that unfold during the dark of the moon. One of them could be the leader type, while others have their own unique skills or personalities that contribute to the group's overall dynamic. For example, one might be really good at solving puzzles, another at physical challenges, and they all come together to face whatever mystery or danger is associated with the dark of the moon in the story.
The main characters include Optimus Prime, the leader of the Autobots. And Megatron, the leader of the Decepticons. There are also human characters like Sam Witwicky.
It's also possible that the main characters are ordinary people who suddenly find themselves in extraordinary situations due to the appearance of the dark moon during twilight. They then have to adapt and figure out how to deal with the new reality that the fanfic presents.
Luigi is the central character in the Luigi's Mansion Dark Moon story. He is the one who is called upon to solve the mystery of the shattered Dark Moon. There are also Professor E. Gadd who provides Luigi with the tools like the Poltergust to help him in his quest. And of course, there are numerous ghosts which range from common ones to more menacing boss ghosts. These ghosts are the ones that Luigi has to capture in order to complete his mission.
The main characters are likely to be Sailor Moon and the other Sailor Guardians. They are the ones who usually fight against the Dark Kingdom.
In the 'Transformers Dark of the Moon Junior Novel', the key characters are surely the Autobots. Optimus Prime, as the leader of the Autobots, plays a crucial role. He is strong, brave and always ready to fight for justice. Bumblebee is another well - known Autobot, who is friendly towards humans. On the Decepticon side, Megatron is the main antagonist. He is power - hungry and wants to dominate the universe. There may also be other Autobots and Decepticons that contribute to the plot with their unique personalities and abilities.