The civil war on Sedri was a battle fought on the planet Sedri. It pitted the Sedrian renegades, under the command of Sedrian bishop of war Karak, and Imperial Aquatic assault stormtroopers directed by Commander Aban, against the Priests of the Sun and their Alliance forces.
During the time of the Galactic Civil War, Karak, the Sedrian bishop of war, challenged the Priests of the Sun's dominion over Sedri. He sought to seize control of the Force-sensitive coral collective intelligence known as the Golden Sun, which the Priests were using. Eventually, Karak gathered a group of rebels who thought all Sedrians should have access to the Golden Sun, but Karak really just desired the coral's strength for himself.
When an Imperial starship stumbled across the water planet and the Imperial forces, commanded by Commander Aban, established an garrison there, Karak saw his chance. News of the planet's discovery spread, drawing Mors Odrion, a diplomat from the Alliance to Restore the Republic, and his companion Rekara.
Karak and his renegades exploited the situation by kidnapping Odrion and taking him to the Imperial garrison. Karak struck a deal with Aban there to form an alliance between the renegades and the Empire to attack the city of Fitsay and seize the Golden Sun's power, dividing it equally between the two groups. The former war bishop kept the arrangement a secret from the majority of renegades, many of whom were wary of the Imperials.
Rekara, meanwhile, managed to get off the planet and went to Delta Base, but she was driven insane after coming into contact with a piece of Golden Sun coral. Rekara later came back to the planet with a group of six Rebels; the group was able to persuade Fala, Karak's daughter, that her father and the Imperial Commander had formed an Alliance, which caused her and some of Karak's renegades to lose faith in his leadership. The former renegades then joined the Rebels and fought alongside them in the ensuing battle to defend Fitsay.
Karak, along with some of his renegades and Imperial troops, then launched their attack. The Imperial soldiers, who were primarily aquatic assault stormtroopers supported by an Aquatic Terrain Armored Transport, engaged the forces of Fistay and the Rebels outside of the city. However, Karak brought six of his most devoted and powerful renegades—Dragob, Glish, K'hondo, Porm, Spodan, and Burborok—as well as his pet razort, Tooch, and their prisoner Odrion, to the Sun caves in an attempt to seize the coral for himself and defeat the Imperials and the Priests.
The High Priest of the Golden Sun Cardo confronted the group at the cave, but one of the renegades attacked him, slashing him across the chest and inflicting a nearly fatal wound. The group then entered the cave, with Karak and Odrion heading straight for the main chamber while the others dispersed throughout the cave to slow down any pursuers. Soon after, the group of six rebels, Rekara, and Cardo's son Pek entered the cave in search of Karak and came upon the enormous chamber. They were then successful in stopping Karak by convincing the Golden Sun to separate and weaken its power, which in turn also weakened Karak, who was later taken into custody and imprisoned for his treachery.
The civil war was not completely ended by the battle at Fitsay. Even though the Empire left its garrison on the planet and off-world traders showed up, the High Priests were open to communicating with the outside galaxy, but they wanted to do so gradually and carefully. Karak's followers, however, thought that the High Priest's stance was impeding Sedri's development.