For Caesar, you can show his ambitious side not just in politics but also in his relationship. He could be determined to make Cornelia the happiest woman, seeing it as another conquest. For Cornelia, emphasize her intelligence. She can be the one who gives Caesar good advice on political matters from time to time.
I'm not sure specifically which 'due unto others real story' you are referring to. It could be about treating others fairly and with respect, perhaps a story where someone learned the importance of giving others their due in a particular situation, like in a workplace where an employee finally got the recognition they deserved.
There could be a character who was once consumed by darkness but is now on a path to redemption through the power of starlight. This character could be a main focus as they struggle with their past actions and try to make amends. Another main character might be a seer or a wizard who can manipulate starlight and uses their powers to fight against the encroaching darkness. There could also be a love interest for one of the main characters, who either supports or challenges their journey in relation to darkness and starlight.