The Fire Nation Intelligence Department (also known as the Intel Department) was created by Firelord Azulon to monitor and control the country's internal affairs. This included spying on Fire Nation government officials, tracking down and imprisoning traitors, and arresting political dissidents. Intelligence Department is actually an informal term for the overextended official name of the department that is unknown to many troopers. Officially, the agency is called the Fire Nation Reconnaissance & Enforcement Department (FNRED) because the name is difficult to remember, it is mainly used in legal documents.
Ozai's Intel Department
The Intelligence Department got a massive extension after Ozai took command of the Fire Nation. Ozai directly increased funding in the department, used them to spy on the Earth Kingdom and Water Tribes, used the Intel Department to gather a database of information regarding the identification documents of Fire Nation families, to track down illegal residents, blackmailing political targets, and for Black Ops missions. Ozai increased the amount of interrogations the department conducted. Ozai's department made a list ranking system that marked names in the orange category that were potential political enemies and in the yellow category if they were high priority targets.
Intel Workers
Intelligence workers were the most common members of the Intelligence Department. Their role was to gather data and manage important documents. While they were trained for combat, it was not their specialty. The average intelligence worker was less dangerous in a fight than a Fire Nation army trooper. These workers wore black uniforms and helmets that didn't cover their faces.
Intel Troopers
Unlike Intel Workers, Intel Troopers were elite commandos who took down high value targets, regularly interrogated "terrorists", went on covert missions, and acted as bodyguards for the Intelligence Director. They had fearsome black armor with white markings.
Intelligence Director
The Intelligence Director was the leader of the Intelligence Department. The Firelord directly appointed the Intelligence Director. An Intelligence Director was meant to a person who is incredibly loyal to the Fire Nation, practical, a natural detective, and adaptive. While the Firelord ultimately could set ordinances for the department, the Intelligence Director usually makes the day-to-day decisions for running the agency. The Intelligence Director also had the ability to request an amendment within the Department's legal limitations to the Firelord and Directors had a good amount of discretion when it came to making decisions.
Director Funik
Funik was the director during Azulon's administration. Funik was known for being practical, prudent, and patient. Funik arrested and imprisoned several political dissidents. However, once Ozai started controversially executing political prisoners, Funik resigned from office. Ozai looked to find a new leader who moved more efficiently and make tougher decisions.
Director Goshal
Ozai personally appointed Director Goshal due to his brutality, ruthlessness, and combat skills. Goshal was completely loyal to Ozai and was more loyal to him than the rest of his country. During the final years of the Hundred Year War, Goshal personally investigated Macai to see if he was loyal to the Fire Nation.
Legacy
The Intelligence Department was remembered throughout history as a fierce government branch that did the Firelord's dirty work. However, Zuko looked to reuse the branch and to change its reputation. Zuko saw the structure of the Intelligence Department as one that could be used to defend citizens, protect vital interests of the Fire Nation, hide dangerous information from the public, to counter real terrorists, and effectively wage war against enemies.