Eternian

Eternians are the near-human inhabitants of twin planets Eternia and Etheria. Once an extremely advanced civilization, they have mostly regressed to a more medieval/barbaric estate, while still retaining some technology from a former era which enables them to travel sporadically between planets and even dimensions. Those of Etheria have been conquered an enslaved by the evil multi-species organization known as the Horde, but have formed a small but steady resistance group. Those of Eternia on the other hand face the frequent threats of former Horde-member Skeletor and his band of minions from all corners of the universe.