Masters of the Universe a third year; however, He-Man often appeared in episodes of "She-Ra" to aid his sister, and several other characters from "He-Man and the Masters of the Universe", both heroic and evil, also appeared in multiple crossovers. She-Ra was born as Princess Adora on Eternia, Prince Adam/He-Man's twin sister and daughter of King Randor and Queen Marlena. As an infant, Adora is kidnapped by Hordak (vampire/demon-faced sorcerer with a cowl of bones, who can transform his body into various mechanical devices) and Skeletor (Hordak's apprentice at the time), and taken to the world of Etheria (a planet ruled by the Horde,
He-Man be a descendant of King Grayskull (a powerful barbarian and a hero from Eternia's ancient past), who sacrificed his life in order to save Eternia from the Evil Horde and originally wielded the Sword of Power. He was the original owner of Castle Grayskull; his sword was concealed in the castle for centuries before being given to Prince Adam, who inherited his ancestor's own power channeled through the sword (thus giving added meaning to the phrase "By the power of Grayskull..."). This action-figure line combined elements from the He-Man universe into a cohesive storyline with biographies on the figures' packaging.