The story might focus on how the relationship between the saintess and the grand duke develops and how it shapes her destiny. There could also be elements of magic and power struggles in the backdrop.
The manhwa likely follows the journey of the saint as they adjust to their new life with the grand duke, maybe facing power struggles and hidden secrets along the way.
It's special because of its unique theme and the depth of the emotions it conveys. The way the story unfolds keeps you hooked. Also, the character designs are really appealing.
Raeliana ended up at the Duke's likely due to a combination of factors. Maybe there was a powerful force at play, or she was drawn there by a quest for something. The complex web of the story's plotlines could be the reason.
Fan Jian was Count Sinan, a count. Although his official position was only the assistant minister of the Ministry of Revenue, due to his close relationship with the Qing Emperor, the Qing Emperor trusted him very much and gave him the authority to command the red-armored knights. Fan Jian had a very high position in the Qing Emperor's heart. The Qing Emperor even left his guards to Fan Jian to command. Fan Jian's strength and status were far greater than that of an ordinary assistant minister. He was also conferred the title of Count Sinan and enjoyed the treatment of an earl. Thus, Fan Jian's title could be said to be quite high.
I don't know for sure as I haven't read it, but I assume the hamster is one of the main characters. And perhaps the northern grand duke is also an important character, given the title of the novel.
The story could involve the saintess growing and developing under the grand duke's care, perhaps encountering magical mysteries or political intrigues along the way.