The only female member of the Evil Warriors, she is an evil witch who aids Skeletor as his second-in-command with her powers of darkness. She is vastly more intelligent than Skeletor's other minions and often comes much closer to defeating He-Man than anyone else (It is often also suggested that she is more cunning than even Skeletor himself, and is merely a member of his ranks while it suits her own purposes). She regularly uses the crystal ball atop her wand to aid with her magic.
For gender diversity, Evil-Lyn was introduced into the Masters of the Universe toy line in 1983 in order to add a female to the Evil Warriors. Initially envisioned as an evil warrior-goddess and counterpart to Teela, Evil-Lyn's action figure is identical to Teela's except in color scheme, head mold and accessories. Although the original figure has bright yellow skin, rarely is this depicted in other media.
Introduced in the pilot episode "Diamond Ray of Disappearance", she is quickly established as one of Skeletor's main accomplices, capable of using all manner of magic spells to battle against the Heroic Warriors. She also frequently employs the use of magical disguises to trick the good guys, in episodes such as "The Shaping Staff", "The Curse of the Spellstone", "Evil-Lyn's Plot" and "The Royal Cousin".
She is also shown to frequently branch out on her own and conduct her own schemes away from Skeletor in episodes such as "Ordeal in the Darklands"; also using her services to aid other villains in "The Defection" and "Eternal Darkness". There seems to be a kind of rivalry between her and Teela, based purely on the fact they are the only women in their respective armies. Although she is seen to have a similar feud with the sorceress Sybiline, as seen in "The Defection".
This is brought to the forefront in the episode "The Witch and the Warrior", Evil-Lyn's strongest episode of the series, in which she is forced into making an uneasy alliance with Teela when the two of them are stranded in the desert together. As well as showing a degree of respect for Teela's skills and intelligence above the levels of pure evil, she also reveals in this episode that she is only working for Skeletor so she can overthrow him once he conquers Eternia.
With her intelligence, fearlessness and her incredible magic skills, Evil-Lyn is clearly Skeletor's most powerful, not to mention reliable ally, often left in charge when he is away from Snake Mountain. Other episodes that feature her working independently of Skeletor include "Journey to Stone City" and "No Job Too Small".
Although her background is never mentioned in the series, the series bible explains she was once a scientist from Earth called Evelyn Powers, who was on board Marlena Glenn's space craft before it crash-landed on Eternia. Evelyn had been insanely jealous of Marlena for being chosen over her to pilot the shuttle. When the ship crashed as the result of an explosion from Skeletor's homeworld of Infinita, Evelyn wound up on Infinita, where the evil powers of that world turned her knowledge of science into sorcery to aid Skeletor. This origin is used in a storybook entitled "New Champions of Eternia" but was unpopular with the show's writers and therefore never alluded to in the cartoon.
Evil-Lyn features in the 1987 live action film Masters of the Universe. Played by Meg Foster, she is shown as Skeletor's main sidekick as in the cartoon, although the film adds an extra dimension to her relationship with Skeletor by indicating a love interest between the two. In one scene, Skeletor indicates that he depends upon Evil-Lyn to portray the image of him as ruler to the people of Eternia. While sharing the desire for power between them, Evil-Lyn's calm and seductive approach is shown to soothe Skeletor's wrath and mania in his moments of hysteria.
Any attempt Evil-Lyn makes to stand closer or equal to Skeletor is quickly deflected in the film. After Skeletor punishes his minions for failure, Evil-Lyn attempts to speak on their behalf. This stance prompts Skeletor to force her into control of his troops on their second mission to Earth to track down the heroes. She succeeds in capturing the Cosmic Key, but Skeletor again disregards her when she reports that she has failed to deal with He-Man.
In the final stages of the film, she deserts Skeletor after he absorbs the power of the universe without sharing it with her. This remains consistent with the various portrayals of the character as scheming and willing to turn on Skeletor from the mini-comics, Filmation series, and 2002 series. Evil-Lyn is not depicted as a powerful magic-wielder in the film (although it is not stated that she does not have such powers either) and does not carry her distinctive orb-staff. In the film she rarely uses magic, although in one scene she casts an illusion to make herself appear to be the dead mother of Julie and also uses her powers to keep the door of the music store closed while Julie brings her the Cosmic Key.
Kevin Corrigan, a human teenager, describes Evil-Lyn's eyes as "strange" during the film. Although no explanation for this is given on screen, Evil-Lyn does not even blink her eyes at the bright light cast from Skeletor's transformation. All of the other characters present, including He-Man, cover their eyes or turn away.
The show's second season expands considerably on the theme of her disloyalty to Skeletor, as well as showcasing her origins. Unbeknownst to Skeletor, Evil-Lyn forms a secret alliance with Kobra Khan to free King Hiss and the Snake Men, whom she believes will grant her greater power than Skeletor. After the release of the Snake Men, Skeletor seeks to punish her by banishing her to the Forsaken Realm in the episode "The Price of Deceit". This episode features a flashback to the time she first met Skeletor, when he was still in the form of Keldor. The young Evil-Lyn had managed to impress Keldor with her great knowledge and power, had fallen in love with him and played a part in saving his life. After his injury at the hands of King Randor, she had taken him to the altar of Hordak, who gave him new life by turning him into Skeletor. After the transformation, Skeletor became more and more twisted and evil, ceasing the love between him and Evil-Lyn and inspiring Evil Lyn to overcome him rather than work alongside him . This episode also indicates there are sparks of good left within her as she considers defecting to the side of good after He-Man saves her life following a call for help from her father.
Later, in the episode "The Power of Grayskull" Evil-Lyn learns that Skeletor promised to free Hordak from the dimension of Despondos in return for having his life saved, but chose instead to destroy his sanctuary, knowing that Hordak could easily destroy him. She therefore chooses to free Hordak by herself in order to gain the power that she needs, and once again concocts a scheme behind Skeletor's back, allying with Count Marzo in the episode "History" to free Hordak from Despondos. Failing in her scheme, she vows to continue until she has freed Hordak. This plot was going to be expanded upon in the show's third season, but the cartoon was cancelled before any further episodes could be produced.