Jewel in the Mist

In his past life, Jule lived comfortably as a young master in 21st-century modern Earth. He took pride in his achievements and boasted his talents, confident that he was set to a successful future. When his father's company goes bankrupt and his family splits apart, Jule is forced away from his luxurious life and treasured home. As if his circumstances couldn't get any worse, the notification from his web novel app proved him otherwise; his favourite novel - Clash of an Independent Sword - has been cancelled. And as if there was nothing to live for anymore, the doors of the train he was on opened from behind him and Jule found himself tumbling down the rough railway track.
He had died.
Well, he thought he had died.
Transmigrated into a world and life paralleled his...except it wasn't.
Jule, who (had tried to) had never hurt a fly (unless it was bothering him), was transmigrated into Clash of an Independent Sword as the annoying minor antagonist years before his first appearance in the novel.

Determined to survive his fate, Jule decides to befriend the novel's protagonist, Borealis Caskut by recruiting him into his duchy's knight order and attempt to change the novel's destiny. But in this world, "fate" and "destiny" isn't what it appears to be. In the end, how do some things change, while others remain the same no matter what?