Castle Grayskull (Revelation)

Castle Grayskull as it appears in Masters of the Universe: Revelation.

History
Originally known as the Hall of Wisdom, this location was the storehouse of all the knowledge of the universe. There, the Council of Elders concentrated their powers into the Orb of Power and to protect the orb, the majestic hall was concealed by the illusion of Castle Grayskull.

Around 500 years before the time of Revelation, King Grayskull was training his two young sons his young sons D'Are and Ro how to use a sword, when the Snake Men attacked his Castle, together with a their newfound ally, the Orlax of Primeria. To combat the Orlax, Grayskull forged the Sword of Power, by merging his own Preternian weapon with another blade made out of Dark ore he procured in the realm of Subternia.

The Grayskulls received aid from a visiting hero from the future, who not only used his own sword to cut off another of the beast's tentacles but also suggested that King Grayskull might disguise the location of the Hall of Wisdom and encouraged young Ro to keep training with his father.

Disguised with the facade of a helmeted skull, the castle was named in honor of King Grayskull. Many guardians protected the castle over the centuries, the most recent being the Sorceress, while an equally great number of hero's used the sword of Power. The first to do so after Grayskull was his son, who became known as He-Ro, and the most recent was He-Man, the most powerful man in the Universe.

The evil Skeletor, who had been trying to learn the secret of Grayskull for years, finally discovered that the castle was merely a shell, and that it's sole purpose was to protect the Orb of Power. The Lord of Destruction used the Shaping Staff to disguise himself as one of his henchmen, Spikor and together with Evil-Lyn, disguised as Clawful, pretended to have been captured by He-Man (in reality the robot Faker). This deception managed to fool the Sorceress long enough for the Evil Warriors to enter Grayskull, after which Skeletor ordered the rest of his forces to launch a full scale attack on the castle, in order to engage the Heroic Warriors and Royal Guards who were bound to come to Grayskull's defense.

Quickly gaining access to the very heart of Grayskull, Skeletor defeated the powerful Nature God Moss Man and maneuvred He-Man into stabbing him with his mighty sword in such a way that the sword would also penetrate the Orb of Power and open it as if it were a key. Skeletor then struck the orb with his own Havoc Staff, cracking it and releasing the magic power that created Eternia and the very universe.

The Sorceress knew that this meant the end of all existence, but was able to freeze time for a short period so that she could confer with He-Man and Teela. He-Man attempted to absorb the magical energy of the Orb with his sword, which split in two. When this happened, his loyal steed Battle Cat transformed back into Cringer and He-Man reverted back to Prince Adam. Skeletor attempted to grab the two halves of the sword for himself, and both he and Adam were obliterated in the explosion caused by the magical impact. The only thing which remained was the top of Skeletor's Havoc Staff.

After these events, King Randor decreed Castle Grayskull to be a forbidden zone. Cringer found the courage to break the law by staying at Grayskull and protecting the Sorceress, who's powers were fading as Eternia had become almost completely bereft of magic. She reached out to Evil-Lyn for help, who in turn hired Teela and her new partner in crime Andra to seek out a magic relic for her. The Sorceress transferred the last ember of magic to Evil-Lyn's staff, depleting herself of the last magic she had left. As she collapsed to the ground, Cringer was there to catch her fall.

Teela reluctantly accepted her new challenge to seek out the two halves of the Sword of Power, which had returned to their places of origin: Subternia and Preternia. It was Cringer who managed to convince her to do so, and he remained at Grayskull to look after the now powerless Sorceress.

Teela sought out her adoptive father Duncan to ask him to forge the two halves of the Sword of Power back together once they found them. But when Roboto offered to take his place, Teela suggested that Duncan go to Castle Grayskull instead to help protect the Sorceress.

Dark Horse prequel comic

 * Masters of the Universe: Revelation No.1 (Dark Horse Comics)
 * Masters of the Universe: Revelation No.2 (Dark Horse Comics)
 * Masters of the Universe: Revelation No.3 (Dark Horse Comics) (mentioned only)
 * Masters of the Universe: Revelation No.4 (Dark Horse Comics)

Netflix series

 * The Power of Grayskull
 * Poisoned Chalice
 * The Forge at the Forest of Forever