After many years of peace on the planet Eternia, the Mystic Wall that has held evil back for so long begins to weaken. As the Royal Palace celebrates the sixteenth birthday of Prince Adam, Skeletor and his Evil Warriors finally succeed in destroying the Mystic Wall. Adam's mentor Man-At-Arms takes the teenage to the mysterious Castle Grayskull where a being known only as the Sorceress explains the history of evil on Eternia, and the very special destiny that awaits Adam...

Prince Adam arrives on the battlefield in the Evergreen Forest to witness the Defenders of Eternia facing defeat at the hands of Skeletor's Evil Warriors. Skeletor and Beast Man take to the skies on their Griffins with King Randor as their captive. After witnessing all of this, Adam hurries back to Castle Grayskull where he seeks out the Sorceress and openly accepts his destiny as He-Man...

The tide of battle turns in favor of the heroes with the arrival of He-Man. With the Evil Warriors at bay, the most powerful man in the universe approaches the heroes and dubbing them the "Masters of the Universe." Leaving the Masters of the Universe to once again battle the Evil Warriors, He-Man and Battle Cat race across Eternia in an effort to save King Randor from Skeletor...

Wanting to prove himself, Price Adam believes He-Man may not be needed if he steps up in battle. Meanwhile at Snake Mountain, Skeletor tells his Evil Warriors that He-Man's sentimentality is his weakness and orders the capture of Adam in order to lure out He-Man into a trap. When Adam is captured by the Evil Warriors he is separated from the Sword of Power, which is sent back to the Royal Palace. Realizing the true urgency of the situation Orko and Cringer journey to Snake Mountain to save Adam...

Preying on the fragile truce between the Andreenids and the Avionians, Skeletor starts a war that threatens to tear the Mystic Mountains apart. As both tribes wage war in the skies of Eternia, Skeletor successfully obtains Ambrosia, a miracle Andreenid food that gives power to the individual who digests it. He-Man and Teela arrive to stop both the war and Skeletor...

An unexpected power surge across Eternia prompts the heroes and villains to search the Sea of Rakash for answers. It becomes apparent that the Coridite crystal, long though destroyed, still exists in the possession of Mer-Man. Man-At-Arms manages to grab the Coridite but Mer-Man prevents the hero from escaping. Just as Mer-Man is about to retrieve the crystal, his large fish ally swallows Man-At-Arms and the Coridite crystal! Unexpectedly, the Coridite causes a mutation inside the giant fish, making the creature extremely powerful and dangerous...

Embarrassed by his mixed-up magical spells, a dejected Orko strays from the Royal Palace. Meanwhile, Skeletor orders Evil-Lyn to steal a powerful artifact known only as the Ram Stone. Evil-Lyn must face her past in retrieving the object, just as a mysterious figure inside Castle Grayskull shows Orko just how important he is in the lives of his fellow Eternians. It is not long before Skeletor has the Ram Stone containing magic strong enough to transform He-Man back into Prince Adam!

After suffering yet another defeat at the hands of the Masters, the Evil Warrors retreat back to Snake Mountain where Evil-Lyn suggests turning the heroes against one another. As Ram Man peacefully fishes on a lake, the boat is hit by a large tidal wave. When Ram Man awakes, Sersi the Siren stands over him telling him that whenever he hears her song he will obey her every command. Little does Ram Man know that Sersi is actually Evil-Lyn in disquise!

Injured during a battle with the Evil Warriors, an unconscious Teela is taken to Castle Grayskull by Man-At-Arms and receives a blood transfusion from the Sorceress. Recovering at the Royal Palace, Teela discovers she now has telepathic powers and subsequently many questions for her father, questions that could lead her to the truth that she is not yet supposed to learn...

Racing their Sky Sleds through the Evergreen Forest, Prince Adam and Teela stumble upon and rescue a large dragon trapped in a cavern by a rock slide. Events soon take an unexpected turn as four dragon babies hatch in the grounds of the Royal Palace and being to cause destruction. The Masters unite and race across Eternia, as the Evil Warriors, aided by the Dragons, attack Castle Grayskull with a ferocity never before seen!

In an effort to prevent Skeletor's evil, Man-At-Arms invents a groundbreaking crystal belt that weakens the villain every time he performs an evil act, or even thinks about doing so. Skeletor is horrified to learn that he can never be evil again, but his Evil Warriors have other ideas. As the heroes believe more peaceful times are upon them Tri-Klops presents to Skeletor a harness, one that will turn He-Man's goodness against him!

When Mekaneck's neck is injured during a battle with the Evil Warriors he is ordered to stay back and act as reconnaissance. Thoroughly depressed and doubting his own abilities Mekaneck seeks solace by a lake where he encounters an old man. Hearing of Mekaneck's woes the old man tells the hero that he could grant him any wish in exchange for a specific Amulet from the Sands of Fire. While Mekaneck heads off to retrieve the Amulet, the Sorceress tells Adam that the evil Count Marzo has returned...

Beast Man introduces Skeletor to the Shadowbeasts, large powerful creatures that attack at night in vast numbers. Knowing the creatures hate any light source, Skeletor and the Evil Warriors cause Mount Barathrum to explode sending out a large ominous could that blocks out the sun. Ram Man must face his fears after Teela is injured during the attack, as the heroes soon realize the Shadowbeasts are striking both the Royal Palace and Castle Grayskull!

With the peace talks between the Speleans and the Caligars having broken down, King Randor, Prince Adam, and Man-At-Arms journey to Subternia to help them reach a settlement. At the same time, the Evil Warriors decide to attack Castle Grayskull form below as all of their other methods have thus far failed. It is not long before the two groups meet in the depths of Eternia...

After receiving a distressing vision, the Sorceress sends Prince Adam and Man-At-Arms to the small island of Anwat Gar to retrieve the Legacy Stones, which are ancient artifacts of great power. However, the pair discovers Sy-Klone, protector of the Legacy Stones, and is soon engaged in combat with the mighty warrior. The battle is interrupted when Skeletor arrives and gains the power of the Legacy Stone!

During a battle with the Evil Warriors, Man-E-Faces' monster guise is taken control of by Beast Man, resulting in feelings of self-doubt for the hero. At Snake Mountain, Skeletor decides to enlist the services of two bounty hunters, Tuvar and Baddhra, in order to eliminate He-Man. The two hunters track He-Man to the Tar Swamp, where only Man-E-Faces can save him. However, Man-E-Faces refuses to play the role of the monster, his most powerful guise...

After failing to impress Skeletor with his latest plan, Tri-Klops decides to overthrow Eternia himslef. It is not long before a near-indestructible army of Bone Monsters are making their way towards the Royal Palace! With the odds stacked against them, He-Man and Sy-Klone defend Eternia as Man-At-Arms latest creation, Roboto, a strategic chess-playing robot, attempts to convince Teela that he can aid them in their battle...

In an effort to strengthen the Masters' defenses, Stratos journeys to the Ice Mountains to retrieve a rare metal called Eternium. Unbeknownst to the hero, Trap Jaw is also after the Eternium, and when the two confront one another, their battle causes them to fall into the caverns beneath the Ice Mountains. Because both are injured in the fall, they decide to form an uneasy alliance, unaware that they are being watched...

When Orko's role of overseeing the gardens at the Royal Palace proves to be a lot more difficult that he first expected, he journeys to the Evergreen Forest to seek out Moss Man. Orko takes some seeds from a strange creature who claims to be Moss Man, only to have the resulting vines overthrow the Royal Palace and capture everyone inside! When the real Moss Man appears, Orko learns that the strange creature he aided was in fact Evilseed!

Buzz-off, along with Orko, journey to Veridas, a land that houses the powerful Crystal of Prasinus. When the pair runs into three giants, Buzz-Off is defeated, and makes his way back to the Royal Palace where he tells no one of the incident. The Masters learn of the problems in Veridas and decide to help, knowing nothing of Buzz-Off's previous encounter. Soon, they discover that his desire for revenge against the giants may actually jeopardize the mission!

All of Eternia is put on high alert when Kobra Khan escapes from the Royal Palace prison compound. The Masters journey to the Mystic Mountains where they inform the mysterious Zokak of the situation. Skeletor is quick to employ the talents of Kobra Khan, unsuspecting of the Snake Man's intent on releasing his ancestors from a hidden void in Snake Mountain...

On Orkas Island, Dekker, the former teacher of Man-At-Arms, is looking forward to a visit from his former pupil. News of the meeting does not go unheard and Dekker is captured by members of Clawful's species. Arriving on the island, Man-At-Arms, Teela, and Prince Adam begin to suspect that there is something wrong when Dekker does not meet them and they see signs of a struggle...

Odiphus, a petty Eternian criminal, witnesses the Evil Warriors victorious over the Masters of the Universe. The small creature journeys to Snake Mountain where he tampers with one of Tri-Klops latest experiments causing an explosion. When the smoke clears, Odiphus emerges as a huge muscular warrior with black and white fur. However, the transformation has given him an awful stench!

In an effort to separate themselves, Tuvar and Baddhra, still trapped in the single form of Two Bad, seek out the three pieces of the Triad of Discidium. The Sorceress alerts He-Man of the situation, explaining that the Spell of Seperation was originally invoked by Hordak, but halted as it began to tear the plant apart! But He-Man is too late, Two Bad has already retrieved the three artifacts and is assembling the Triad of Discidium.

He-Man and Battle Car are overpowered by Skeltor's newly formed Council of Evil, but manage to escape capture by transforming back into their other selves. Alongside Teela, they attempt to free the Masters, but fail with Adam losing his Sword of Power in the process. An injured Prince Adam and Cringer journey back to Castle Grayskull when they realize Skeletor is on his way to conquer it. The pair stand in defense of the castle as the Council of Evil and the escaped Evil Warriors arrive in Force!