It's been a while since I thought about this game.
Manhwa Au with Mystic Messenger.
Jumin is the crown prince with the foolish father of an emperor. He doesn't care about whether he will become emperor or not, but since it's expected of him, he does stuff anyways and flawlessly.
Zen is the 2nd in line, brother from another mother prince. He's been constantly compared to his half brother so tries to differentiate himself and work on his own image in hopes of getting the throne.
Seven sure is the all powerful duke that's a bit of an outcast towards society. Has connections with the underworld. Is very lonely. Doesn't obey anything the empire says.
Yoosung, the aspiring knight that becomes MCs bodyguard. Will at some point take an almost near death hit for MC. MC heals him and he dedicates his life to her. The best friend to MC tbh.
V is the random mage, probably in this universe he's a major player in the underworld and travels around.
Ray is Vs disciple and is unaware about the deal V and Seven have made with each other. Is unaware he even has a twin brother.
Jaehee is the captain of the gaurd and Jumin's personal gaurd. Since he doesn't need one often, more as a formality, she does secretary work or train the Knights. She saves MC in a kidnapping attempt as least once.
Rika -> Actual MC of the novel turned onto a villainous because the plot has changed.