The Nine Great Palaces of the Nine Underworlds Demon Palace were extremely special even within the Devil Palace.
They were similar to sects and lineages within a territory, specially responsible for continuously replenishing the Nine Underworlds Demon Palace with gifted bloodlines.
The Nine Underworlds Demon Palace had an extremely complete organizational structure.
The Nine Great Palaces had only two ways of selecting martial artists.
The first was for martial artists who were native to Nine Underworlds City. After awakening their martial souls, martial artists at the Heaven Grade or above were qualified to choose one of the Nine Great Palaces for cultivation.
The second was for martial artists from the Devil Realm Eastern Region.
They would be recommended by the various branch helms.
If the branch helms throughout the Devil Realm Eastern Region discovered a gifted disciple, they would recommend that disciple to the main helm of the Devil Realm Eastern Region. After the main helm investigated and assessed the disciple, confirming that the disciple was indeed a gifted martial artist with cultivation value, it would recommend the disciple to Nine Underworlds City.
After receiving Nine Underworlds City's permission, the recommended disciple would be secretly sent to Nine Underworlds City, where the disciple would undergo another assessment by the Nine Underworlds Demon Palace.
After passing the assessment, the disciple would be qualified to choose one of the Nine Great Palaces, formally join it, and begin cultivating.
Of course.
Whether they were native martial artists of Nine Underworlds City or martial artists recommended by the branch helms of the Devil Realm Eastern Region, joining the Nine Great Palaces was not the end. It was the starting point of everything.
The Nine Great Palaces had exceptionally rigorous studies: a minor examination at the end of every year, a major examination at the