Skeletor tricks He-Man into thinking he has accidentally killed a man and, consumed by guilt, He-Man transforms back to Adam and drops his sword down the abyss of Grayskull, deciding he is no longer worthy of Grayskull's powers. Skeletor then opens a portal to the goblin world, enabling General Tataran's army to enter Eternia, with possibly enough power and strength to conquer the planet. Can Eternia survive without its greatest hero... and will Adam realize he has been tricked before it is too late?

He-Man's sword is taken by a peaceful race of Rock People who believe the sword gives them power. Fearing that himself and Battle Cat may never be able to become Adam and Cringer again, He-Man must journey to the underground world of the Rock People to recover the sword.

The Sorceress sends He-Man, Man-At-Arms, Orko and Battle Cat back in time after Skeletor, who, with Tri-Klops and Fang Man, has gone back into Eternia's past to plant an effective time bomb on the spot where Castle Grayskull now stands, that will destroy it in the present unless He-Man manages to stop it "in time"...

When exploring an ancient temple, Prince Adam and He-Man come across the Masks of Power, which conceal the spirits of an ancient evil race. Two power-hungry travellers steal the masks, and their bodies are possessed by the spirits within them. Together they go to Snake Mountain, where they offer Skeletor their services- but Skeletor will only recruit them after they have passed a series of tests, one of which involves recovering the Sword of the Ancients from deep within Snake Mountain.

Skeletor has managed to find the legendary 'Diamond Ray Of Disappearance', a mystical jewel that sends who or whatever it is aimed at vanishing into another dimension. Calling his warriors from around the Universe, Skeletor plans to use the magical gem to get rid of He-Man once-and-for-all. His first victims are King Randor, Queen Marlena, and Man-At-Arms, as well as The Sorceress of Grayskull, and it is up to He-Man to destroy the jewel, freeing his friends from the distant limbo-like dimension that they are trapped in...

An inventor called Zicran visits the Royal Palace to deliver a Transmutator machine to Man-At-Arms, accompanied by his daughter Ileena, a friend of Teela's. Ileena is vulnerable and lacking in self-confidence, feeling inferior compared to Teela's agility. Meanwhile, an evil sorcerer called Jarvan, who was previously defeated by He-Man and Man-At-Arms, has escaped from the prison mines and has set his sights on the Transmutator. Preying on Ileena's depression, he disguises himself as a kindly old woman and gives Ileena a 'magic potion' that will boost her confidence and strength. But the potion contains a dangerous drug, and Ileena soon finds herself addicted to the drug, and almost causes several serious accidents while under its effects. She also finds herself unwittingly obeying Jarvan's commands, and helps him to obtain the Transmutator! Can the heroic warriors cure Ileena's addiction before she causes more damage to herself and the people around her?

While entertaining the Royal Family with his magic, Orko finds his act interrupted by a strange sorceress called Majestra. Majestra performs a trick in which she appears to make the King vanish then reappear- but in fact, Majestra is really Evil-Lyn in disguise, and has teleported the King to the dungeon and replaced him with a disguised Beast Man! Evil-Lyn has found a magical Shaping Staff which can transform anything into whatever the holder wishes- and under their disguises, Evil-Lyn and Beast Man set about causing havoc around the palace, turning each member of the Royal Family into helpless animals, while Skeletor awaits them at Grayskull with his latest creation- an evil version of He-Man, called Faker!

Negator, an evil character with a love of computers and electronics, sees Man-At-Arms testing out his latest invention, the Beam Ray, in the desert. Impressed, Negator wants the scientist to come and work for him, so that he can use his creations for his own evil purposes. When Man-At-Arms refuses, Negator captures Teela to force him to come to him. As He-Man, Ram Man and Battle Cat search for their missing friends, they are sucked into Negator's underground electronic domain, and Negator sends He-Man and Ram Man into his living electronic "game"...

Evil-Lyn captures Mira, the daughter of the powerful wizard Kor, and frames He-Man and Man-At-Arms for the capture. Kor takes He-Man and Man-At-Arms prisoner, and refuses to listen to their pleas for innocence, planning to unleash a demonic entity called the Crimson Scourge upon them unless they reveal his daughter's whereabouts.

For many years, the Royal Palace of Eternia has had shipments of photanium (the strongest metal in the Universe) from the moon of Phantos to make weapons with, but Skeletor intends to from now on step in and have the photanium all for himself. Man-At-Arms is given worthless ore instead of the photanium, and when the moon's ruler, Queen Elmora, puts up a fight against the plans, Skeletor casts a spell on her that ages her and turns her evil. Realising the metal they've been given is useless, He-Man and co. head to Phantos to see what's going on, only to find themselves on the moon where Skeletor now drives slaves mining for the metal...

Angered by his continual defeats, Skeletor blames Beast Man, banishing him from Snake Mountain and his evil forces. Meanwhile, King Randor is preparing for a Royal tour of Eternia, accompanied by Man-At-Arms and a guard of his choice. The King chooses He-Man, but Adam, upset that he always has to play down his qualities to hide his alter-ego, convinces the King to choose him instead. Beast Man spots the touring party, and aided by his Shadow People followers, he ambushes them. Determined to prove his worth to his father, Adam resists transforming into He-Man and instead tries to stop the attack as himself, but he is overpowered, and Beast Man captures Randor, intending to use his capture to win his way back into Skeletor's good books...

An ambassador from another kingdom visits the Royal Palace to present King Randor with a gift. But Man-At-Arms recognises the man as Skeletor in disguise, and in an attempt to stop him, is turned into a crystal statue. He-Man and Teela must journey to the Isles of Darksmoke, where the great and ancient dragon Granamyr knows the only spell to reverse the effect on Man-At-Arms. But their task proves far from easy- for not only is Granamyr suspicious of humans and reluctant to help them, but he says he will only give them the spell if they cut down the living tree named Skytree. Will He-Man willingly take a life if it is the only way to save that of his friend?

Skeletor has gained control of the Cosmic Comet above Eternia, and intends to use it to blow open the jaw bridge of Grayskull. He-Man, Teela, Man-At-Arms, The Sorceress and Orko set out to stop Skeletor's scheme, with the help of Zagraz, a wizard with power over comets.

An evil wizard called Tauron casts a spell on Orko's Uncle Montork and his pet Gark, turns them evil and sets them on Grayskull!

He-Man and Man-At-Arms set sail to investigate the disappearance of some of King Randor's food ships. Sucked beneath the surface by a whirlpool, they find themselves in the underwater city of Aquatica, which has been taken over by Merman. Merman has kidnapped the city's princess, Nahmi, and is controlling the Aquaticans with the Pearl of Power! But he has convinced them that the surface dwellers kidnapped Nahmi, and the Aquaticans have waged war against the people of the surface. Can He-Man help the Aquaticans see the light, and rescue Princess Nahmi before Merman creates more havoc?

Zodac comes to Grayskull and tells The Sorceress that Eternia is in great danger as Skeletor is searching for the Starseed, the single most powerful object in the universe- a small chunk of cosmic matter left over from the big bang, which can turn its holder's thoughts into reality. The Sorceress summons He-Man, and together with Battle Cat and Orko, he sets off on a race to reach the Starseed before Skeletor does. But given that the Starseed is able to give anyone all the power that they want, is even He-Man strong enough to resist being corrupted by its power?

A fierce electrical storm brings electronoid Aramesh – a robot made of pure energy – to Eternia from Orko's dimension. He is hunting for Orko, who years ago was entrusted to guard a powerful magical sphere. Skeletor oversees Aramesh's arrival and decides that he could use him to his advantage...

Palace Eternia has run out of Eternium, the fuel which generates all power in Eternia. A young boy called Chad finds a sample while practising his training with his grandfather in the desert, and He-Man and Teela set out to collect it from them. But the Eternium is stolen by Trap Jaw, who intends to use it to gain equal power to He-Man! As He-Man fights to recover the Eternium and stop Trap Jaw, Chad learns a thing or two about the real dangers of fighting.

A villain called Azrog is arrested on Trolla by Uncle Montork, but he flees to Eternia where he joins forces with the witch Spydra. Montork follows him, but ends up imprisoned in Spydra's castle. When He-Man, Battle Cat, Teela and Orko go to rescue Montork, Orko falls under Azrog's spell and becomes evil, and is set against his friends.

Whilst on an archaeological dig, Man-At-Arms and Professor Smallen are taken captive by ancient robots called Zaktons, who were left by the Ancient Ones to guard the ruins of the desert. He-Man and Teela head to the Ancient Ruins to save them, but they also face danger from Trap Jaw, who wants the Zaktons' artifacts for himself.

Orko's friend Podi runs away after an accident at the Royal Palace and is captured by her father's longtime enemy, Rago. Rago has plans to use Podi for his evil schemes.

Skeletor's latest invention, the Collector, is capable of bringing stone statues to life and turning people to stone. With Beast Man, he attacks the Royal Palace with the new device, bringing court-yard statues to life and freezing Man-At-Arms in stone. If the effect isn't reversed by sundown, he will be cast in stone forever. As He-Man, advised by The Sorceress, goes to search for the one thing that can aid them in reversing the spell, Skeletor uses the energy the Collector has taken from his victims to awaken an ancient, giant statue, and turns it on Castle Grayskull...

Skeletor and Evil-Lyn break into the temple of the Fire People and steal the Spellstone, with which they unleash a terrible storm. While He-Man, with Ram Man, Stratos and Battle Cat, goes off to try and retrieve the Spellstone, Evil-Lyn magically disguises herself as an old lady, and convinces Eternia's peasants that the storm was a result of the Elders being angry at the Royal family. She soon convinces them to unleash the Creeping Horac - an ever-growing weed-like entity that covers buildings and gradually sucks away the air - onto the Royal Palace...

When King Randor's beautiful but snobbish and stuck-up niece Lady Edwina comes to stay at the Palace, Orko is attracted to her and tries unsuccessfully to impress her. He thinks back to a magical medallion that he once had when he arrived on Eternia years before in a freak storm, when he saved a young Prince Adam and Cringer from the Tar Swamp, losing the medallion in the process. He heads off to the swamps to try and find the lost charm to impress Edwina, but unfortunately he is there at exactly the same time as Skeletor, who, with Evil Lyn and Beast Man, has come up with a magical potion to resurrect ancient beasts from the swamp to use in an attack on the Royal Palace...

Skeletor and his latest allies, the tribal-like Torgs, are trying to awaken Mulkram, a giant, diabolical monster who was frozen by the Elders centuries ago to stop his reign of terror. He-Man, Teela, Man-At-Arms, Orko and Ram Man are in the city of Avion for the annual ceremony where Stratos presents the magical Staff of Avion to his people, but just as the ceremony is about to begin, the Torgs attack, capturing Stratos and the staff. Skeletor intends to use the staff's amazing powers to awaken Mulkram, and to use the mighty creature to enter Castle Grayskull...