In general, when a country has a difficult case, the king will appoint an imperial envoy to handle it and give him a lot of power. First of all, you can call all local resources to help with the case. The imperial envoy arrived at the scene of the incident. Because he has an imperial edict, which represents the highest power level of the feudal dynasty, you can call the local army, county government and other official institutions at will to make the process of handling cases smoother.
Secondly, the imperial envoys have the power given by the king to act first and then act. Even if the other party's level is higher, all participants or organizers of such serious cases can be punished before reporting, which greatly simplifies some unnecessary procedures and avoids some complicated relations between the DPRK and China.
Imperial envoys are not a long-standing official position. Just to deal with some sudden and serious things, they are appointed temporarily by the king and have higher privileges than the official positions in the ordinary establishment, but these privileges can only be used for the handling of related cases. If you abuse your power and seek personal gain, the punishment faced by an imperial envoy is also very serious, and the highest can even be sentenced to death.
When Lin Zexu went to Guangzhou to ban smoking, he was appointed as an imperial envoy by the central government. When smoking was banned, he mobilized all his strength to investigate and collected most of the opium in Guangzhou and its surrounding areas, and finally destroyed it. Apart from the king, there is only an imperial envoy appointed by the king who can temporarily mobilize so much manpower and material resources to carry out this work and unite all forces to try their best to help. Therefore, in ancient times, imperial envoys were temporarily empowered, and no one could match them except the king.