The Eldritch Mist

She-Ra and Swift Wind are flying to visit Castaspella in Mystacor, when they spot a Horde Slave Camp, where the prisoners are being forced to work at excavation labor. They fly down and free the slaves, who race to the Horde transport and use it to escape. Having dealt with that threat, She-Ra and Swift Wind continue on to Mystacor. Shadow Weaver watches them leave, and vows to make the rebels prisioners of their own

Episode of She-Ra: Princess of Power (1985-1987), Filmation.