This magically enhancted stone wall encircled the entire world of Eternia's equator and separated the Light Hemisphere from the Dark Hemisphere. It was created in the last days of the rule of the Council of Elders when an ambitious warlord called Keldor stormed the Hall of Wisdom with his Evil Warriors in order to claim the great power of the Elders for himself. However, Keldor was defeated and badly wounded as a result which led to the Masters of the Universe forcing them to retreat to their stronghold at Snake Mountain in the Dark Hemisphere. In order to contain their evil, Man-At-Arms and the Sorceress of Castle Grayskull worked together to raise the Mystic Wall that was a powerful barrier that separated the two sides of the world. This allowed King Randor's reign to continue in peace whilst the world was saved from the dark desires of Keldor.
Despite this being the case, it had been long foreseen by the Elders and the Sorceress that the Wall would one day be breached. This was because the newly named Skeletor had made repeated attempts to breach the barrier but had failed. However, he finally created a device that was designed to create an instability in the Mystic Wall. Whilst he possessed the means, he lacked the appropriate power source and sent his henchmen Mer-Man to search through the Sea of Rakash for a crystal; a task that took two years to complete. Mer-Man was successful and the crystal was inserted into the device where it fired a powerful blast into the wall revealing a fracture in it. Whilst not enough to destroy the wall itself, the device had revealed a weak point in the Mystic Wall which allowed the Evil Warriors to combine their strength in order to destroy it. The Mystic Wall was finally destroyed by Skeletor who used his Havack Staff to obliterate it entirely. He later stood laughing as the barrier collapsed around him as it signalled his freedom and his plan to conquer Eternia by claiming the power of the Elders once more.