WITHIN THESE WALLS... ARMAGEDDON!
This part of the story begins at the point when Zodac joins the battle. After vanquishing the demon horde, Zodac tells He‑Man that Skeletor would not have sent the creatures and thereby jeopardised his own plan. He reveals that there is a manipulator at work but refuses to say who it is. Once again the supposedly neutral characterisation of Zodac spoils the story. His role seems only to be to remind He‑Man that the choices he makes could have perilous consequences for either Eternia or the Goddess. However, he does use the talismans to summon Zoar, the mystic falcon, for a purpose not yet revealed.
Elsewhere we see the secretive observer is none other than Damon, the sorcerer who once terrorised Ceril's people. There's obviously a profound enmity between him and Skeletor. Damon is revealed to be in possession of both halves of the Power Sword, but he can't retrieve them because they are held in a stasis field of the Goddess's design. Skeletor begins to lose patience with the heroes and apparently wonders how someone is interfering with his plan. A creature conjured by Damon attacks Skeletor, but Skeletor destroys it and confronts his old adversary. More history between them is revealed. Damon, as an Eternian, objects to the presence of the alien Skeletor.
Man‑E‑Faces arrives at Castle Grayskull, unsure what has compelled him to go there. Suddenly there are incredible flashes of lightning and explosions in the night sky, and the warrior is transported inside the fortress. Elsewhere Skeletor and Damon fight, and Skeletor claims he's been aware of Damon's strategy to combine their power in order to enter Castle Grayskull from the beginning. Skeletor wins the fight and Damon appears to die in a fiery end. He‑Man and his friends find themselves inside Castle Grayskull. A series of obstacles are encountered before a final confrontation with Skeletor.
Skeletor transforms Man‑E‑Faces into his monster form and orders him to attack He‑Man, but He‑Man wins the fight and goes for Skeletor. In another dimension, Zoar locates the Goddess. Their melded power overcomes the magic shields holding the Goddess. Skeletor gains the Power Sword but his success is shortlived when Zoar arrives and snatches it away. He‑Man knocks the evildoer unconscious. The Goddess says she will hide the sword again, and the quest is over. While some elements are left unexplained, this is a good end to a satisfying tale. The complete three-part saga stands with the original minicomics as key MOTU lore.