He-Man and the Masters of the Universe (1983)

In a distant and mystical land, wimpy Prince Adam leads the life of royalty. Unknown to all but a few close friends/allies, Prince Adam is actually a hero, the mighty He-Man. Together with his friends, (such as Teela; her father, a man-at-arms; mysterious Orko and his mighty friend/horse substitute Battle Cat), He-Man battles the evil Skeletor and his minions for control of the world, and, more importantly, for the control, power and "honor of Greyskull," the mysterious castle from which He-Man derives his powers.