The background is the well-known Kowloon Seizing of Heirs.
The main plot is the emotional life of eighth elder brother Yinsi
The secondary line is about the brotherhood of several elder brothers from childhood to the intrigues of competing for the throne as adults.
This article has many discrepancies with history, and those who follow history will avoid it.
Well, my personal writing skills are limited, so be careful when entering.