Katarn, now Emperor, commands that the revolt be put down with extreme prejudice.
Roughly around the time that Kyle Katarn seized control of the Valley of the Jedi, becoming the Galactic Emperor circa 5 ABY, the Rebel Alliance began an uprising against his rule on the planet Danuta. To quell this rebellion, Emperor Katarn dispatched Sariss.
This rebellion is only referenced within the dark side ending, which is not considered canon, of the video game Jedi Knight: Dark Forces II.