These complete the Dread Master story arc that starts with the Imperial Belsavis planetary quest and continues through KP, EC, TFB, the Seeker Droid missions, Section X and SNV.
Both are required to complete the Oricon planetary series. Dread Fortress is first and Dread Palace is second. Progressing the Oricon quest line is required to unlock the one time for both.
The one time is on Oricon at the base camp. Little Kephi may or may not appear….