He-Man and the Masters of the Universe

A spacefaring gladiator called the Game Master lands on Eternia, intending to capture He-Man to make him fight for his amusement. But when he sends his minions out to find He-Man, he is in the form of Adam and so He-Man is nowhere to be found. So instead they capture Teela- but they also take Adam's Power Sword, meaning he is faced with the task of rescuing Teela as Adam!