Korus, a male Human from the Empress Teta system, held the position of royal instructor to Aleema Keto and Satal, the future leaders of the Tetan throne. Subjected to constant ridicule by the Keto siblings, Korus secretly acted as a spy for Lord Keto, father to Satal, providing information on his son and niece's activities. After Satal and Aleema, who had since established a Sith cult called the Krath, discovered Korus's clandestine activities, they employed their newly acquired dark side powers to deceive him into thinking his tongue had become an Adegan eel.
In 3997 BBY, Korus, bearing the marks of their cruelty, accompanied the Krath when they launched an assault on the Tetan carbonite smelter in orbit around Empress Teta, declaring themselves the new authority of the Tetan planets. He was then compelled to reveal his disfigured mouth before lapsing into unconsciousness, becoming the only Tetan official to survive the resulting slaughter. Subsequently, Korus was forced into servitude by the Krath, who subjected him to further torment by sewing his mouth shut. Following a minor error that led to the staining of Aleema's dress, Korus met his end—incinerated by Sith magic.
Korus, a male Human hailing from the Empress Teta star system, was in the service of Lord Keto, the Emperor of the Tetan Monarchy. His role was to educate Satal and Aleema Keto, the Force-sensitive heirs to the throne—the son and niece of Lord Keto. Korus was tasked with teaching them royal customs and fundamental knowledge from their early years. During their lessons, the children were told the story of the Krath, a legendary magician-god, a tale that would stay with them as adults. As Satal and Aleema entered adolescence, Lord Keto and his sister Magda grew wary of their children. Consequently, Korus was instructed to spy on them and report their actions. This generated feelings of disdain in Satal and Aleema towards Korus, who they now saw as a treacherous pawn of their parents. Despite this, Korus remained committed to his duties, continuing to monitor the activities of the royal children while relaying his observations to their parents.
In 3997 BBY, Korus permitted Aleema and Satal to journey alone to the Galactic Museum on Coruscant, the capital world of the Republic. Unknown to him, their trip was motivated by their interest in the dark side of the Force, specifically the history of the Dark Lords of the ancient Sith Order. The Ketos encountered Sith magic during their travels and transformed themselves into the Krath cult, named after the magician-god from their childhood stories. Korus was present when Satal and Aleema returned, and the Ketos, now wielding Sith abilities, decided to exact revenge on their royal tutor for his betrayal to their parents. To prevent Korus from further informing on them, Aleema used her powers to transform his tongue into an Adegan eel.
The Krath also aimed to supplant their parents as the rulers of Empress Teta and planned a political takeover of the entire system. During Lord Keto's yearly inspection of the Tetan carbonite smelter in orbit, Korus was compelled to accompany the Krath as they raided the space station, acting as their escort. He was fully aware of the breach of protocol represented by the Krath's presence during official state matters, but he was powerless to stop it. As the Krath approached the group of Tetan officials, Lord Keto demanded that Korus explain his insubordination. Korus's attempt to respond revealed that he had an Adegan eel in place of his tongue, horrifying the Tetans and causing Korus to fall into a catatonic state.
Korus awoke to discover that Lord and Lady Keto, along with the other Tetan officials and members of the Carbonite Guild present on the orbital smelter, had all been killed by the Krath. With all resistance eliminated, the Krath seized control of the Empress Teta system. They established their headquarters in the Iron Citadel of Cinnagar, where Korus was reduced to serving Satal and Aleema. As a further act of cruelty, Aleema sewed Korus's lips shut, forcing him to serve his masters food and drink while enduring their constant mockery. His servitude was short-lived, however. While carrying wine ordered by Satal for dinner, Korus tripped and dropped the decanter, spilling the drink all over Aleema's new gown. Before Korus could clean up the mess, she unleashed the dark side upon him and burned him alive, to the amusement of those present. Korus's death marked the end of the old Tetan regime, solidifying the rule of the Sith-inspired Krath.
Korus was an older man with graying hair and a somewhat portly build, often described as fat by Lord Keto and his son. His submissive nature contributed to the blatant disrespect he received from those around him, as evidenced by the contempt repeatedly shown by Lord Keto, Satal, and Aleema. The younger Ketos considered Korus a deceitful weakling and used an illusion to replace his tongue with an Adegan eel to prevent him from acting as Lord Keto's informant. Korus was further humiliated when his former students later sewed his mouth shut and forced him to serve them as a servant. His life held no value to Aleema, who killed Korus in a fit of anger without remorse, instead reveling in the manner of his demise.
The character of Korus first appeared in Tales of the Jedi – Dark Lords of the Sith 1, authored by Tom Veitch and Kevin J. Anderson. Korus also featured in John Whitman's full-cast audio rendition of Veitch's and Anderson's Dark Lords of the Sith. In both versions, Korus has no spoken dialogue, as he is introduced after his tongue has already been replaced with the Adegan eel. Instead, he makes muffled sounds, audible in the audio drama, as if his mouth were full.