This was because of the special nature of his clan's bloodline; once detected by Karl Akmond, the commander of the Burning Legion, it was very easy for him to control through the bloodline. Therefore, the prohibition was particularly strict for the Akmond family.
As a result, the Akmond family, which initially had the potential to promote to Medium Divine Power and even had a great opportunity to advance to Powerful Divine Power, declined.
Until now, the decline of the entire family left only Karl Akmond with Weak Divine Power emerging as an anomaly within the Akmond family. His bloodline was unusually thick, and he had been very strong since childhood, coming close to making it onto the secondary list of prodigies now.