This ancient invulnerable relic was created long ago on Eternia by dark mystics that served the warlord Hordak. Many years ago, Hordak ordered the creation of the Triad in order to split the planet in half by conducting the ritual at the Well of Darkness where the Spell of Separation was made. This act led to the creation of the Light Hemisphere and its counterpart the Dark Hemisphere. It was Hordak's belief that the latter of the two would prove to be a safe haven for his minions through which he could continue the conquest of Eternia. However, even the leader of the Evil Horde underestimated the magics that were released and stopped the ritual from being completed as it nearly destroyed the entire world. Giving the order to his sorcerors, the Triad of Discidium was split into three parts and scattered to various parts of the globe in order to prevent their usage again.
Only faint knowledge of the Triad remained within ancient tomes which spoke of the Spell of Separation as well as the dangers involved in reassembling this artifact. In later years, the Evil Warrior Two-Bad grew tired of sharing their respective bodies with one another and thus sought a means of returning to their former slaves. Upon listening to the advice of Stinkor, they travelled to meet Vormus who was an expert in various spells and potions in the Dark Hemisphere. After arriving, they asked for a Spell of Separation but upon reading the tome - Vormus refused to give Two-Bad the tablet. However, the bounty hunters simply took it from Vormus and began their quest in assembling the Triad of Discidium. Their acquisition of the first part of the relic alerted the Sorceress of Castle Grayskull who summoned He-Man in order to prevent Two-Bad from unwittingly destroying Eternia.
Two-Bad managed to gather the three pieces and reconstructed the Triad whereupon he placed it at the Well of Darkness in the belief that the Spell of Separation would return him to Tuvarr and Baddhra. But the resultant storm that formed as the Spell was created caused them to flee as the planet began to rip itself apart. It was only the actions of He-Man who returned the three pieces back to their original places did the planet get saved from certain destruction.