Eternia is the setting of the MOTU saga. It is a planet that visibly blends genres: medieval fantasy castles next to high-technology vehicles, sorcerers alongside cyborgs, palace politics alongside cosmic threats from beyond the stars. The Light Hemisphere is the seat of the Royal Palace and most of the Heroic Warriors; the Dark Hemisphere contains Snake Mountain and the haunts of the Evil Warriors.
The world is ruled by King Randor and Queen Marlena from the Royal Palace. Castle Grayskull, though situated within Eternia geographically, is its own sovereign entity guarded by the Sorceress. The 2002 MYP series introduced King Hsss and the Snake Men as a third threat to Eternia, expanding the world’s geopolitics significantly.
Catalogue source: heman.fandom.com (CC BY-SA 3.0).
