Plot
In Eternos, the capital city of the planet Eternia, young Prince Adam and his friend Teela are trained in the art of battle by Duncan, the king's Man-At-Arms and Teela's father. The city is attacked by forces led by warlock Skeletor, who captures Adam's parents, King Randor and Queen Marlena, while Duncan is gravely injured by mercenary Trap Jaw. The Sorceress, guardian of Castle Grayskull on the outskirts of Eternos, sends Adam through a portal to Earth, Marlena's homeworld. She entrusts Adam with the Sword of Power, and Adam escapes but loses it.
Fifteen years later, an adult Adam works in human resources and lives with his friend Hussein in Oklahoma City. Obsessed with finding the sword, Adam eventually receives an anonymous tip via text message and reclaims it at a comic store. The next day, Adam is arrested for the sword's theft, but is stopped in transit on a freeway where he is attacked by Skeletor's lieutenant Beast Man. He is rescued by Teela, alerted after Adam touched the sword, and they escape in her ship to the ruins of Eternos, where the warriors of Eternia live in hiding from Skeletor's rule.
Offended by Adam's childhood nicknames for them, the warriors dismiss him as a nobody and imprison Adam and Teela with Duncan, now a drunk, and Roboto, a combat robot reprogrammed as a servant. The four escape and convince the warriors, including Fisto, Ram-Man, Dian and Mekaneck, to trust them. They are attacked by Skeletor's forces, and Trap Jaw stands in their path to board Teela's ship. Adam uses the sword to summon the power of Grayskull, transforming into a warrior, and defeats Trap Jaw.
Skeletor captures the others after Adam, Duncan, Roboto, and Teela flee, and executes Moss Man, forcing Fisto to admit that Adam has the sword. Skeletor reveals to Adam that his parents are alive and demands the sword as ransom. Adam, Teela, and Duncan reach Skeletor's lair at Snake Mountain, where Adam defeats Skeletor's personal guard and faces Skeletor, but Randor is mortally wounded in the ensuing cave-in. Knocked unconscious, Adam changes back into his mortal form as he and the others are imprisoned with Marlena. While imprisoned, Adam reunites with his tiger companion Cringer.
Skeletor discovers that he cannot access the sword's powers and his counselor, sorceress Evil-Lyn, suggests a ritual at Castle Grayskull. Adam and his comrades escape to Eternos and lead Fisto, Ram-Man, Dian, and Mekaneck against Skeletor's army. Duncan fights and kills Trap Jaw, but Roboto is destroyed. Riding on Cringer, Adam and Teela break into Castle Grayskull where Adam duels Skeletor, Teela takes on Evil-Lyn, and Cringer faces off against Beast Man. Skeletor shatters the Sword with his Havoc Staff, stabs Adam and proceeds to telepathically torment him inside his memories of Earth.
The Sorceress appears to Adam and explains that it is he, not the Sword, that truly harbors the power of Grayskull. Now free, Adam reconstitutes the Sword, summoning the power of Grayskull to transform into Eternia's champion once again. Adam tries to use his Earth-learned wisdom to negotiate with Skeletor, who rejects his peace offering. The two battle until Adam overpowers Skeletor, ultimately defeating him by reflecting his staff's power, destroying it and disintegrating his body. Meanwhile, Evil-Lyn flees.
Six months later, Marlena now reclaims rule over Eternos, where Adam and his friends welcome a refurbished Roboto as well as Hussein, who sees for himself that everything Adam told him was true. Teela asks whether Adam has a heroic name for himself, and he decides to call himself, "He-Man". Responding to a distress signal from an Avion village, Adam and Cringer leap into action as He-Man and the newly-armored Battle Cat.
In the town square, the Trollan magician Orko appears, breaking the fourth wall, telling viewers the morals of the story. Later, as Marlena watches He-Man and Battle Cat charge into battle, she tells Duncan she has given up hope for reuniting with both her children, while Duncan is more hopeful for her daughter's return. Elsewhere, Adam's long-lost twin sister Princess Adora discovers the Sword of Protection near the Fright Zone on the planet Etheria. Meanwhile, Evil-Lyn returns to Castle Grayskull to retrieve Skeletor's skull. As she leaves, Skeletor's laughter is heard.
