I Screwed the Novel's Plot

WARN: SLIGHT ROMANCE!! NO HAREM!! FAMILY GENRE!! Filled with political intrigue, warfare, adventure, friendship, and betrayal. --- Synopsis: I transmigrated into a novel that I read years ago as the second Prince of the Chrono Empire and was fated to be killed by my half-brother, the First Prince at the age of 12. So, What's my role in this novel? Am I the villain? Am I an insignificant extra? Am I the protagonist? Nah, definitely not. But, why bother? Following the novel's plot isn't my style and I won't let it dictates my life. Regardless of my role, I am the main character of my own life.