The North Courtyard is where the Immortal Lord cultivates his personal guards, so it is jointly managed by the eight kings, though each has very clear and distinct duties.
They take turns managing the cultivation of the various prodigies in the North Courtyard. If a disciple is talented enough to catch their eye, they will have the opportunity to enter the Taiwu Guards and become one of the Immortal Lord's personal guards.
This is a supreme honor, and virtually all the disciples in the North Courtyard break their heads trying to get in.
Chapter 875