Other than Prince Sky and Brandon, the following characters are from the planet Eraklyon.
King Erendor & Queen Samara: The parents of Sky. They 1st appear in season 1, episode 17, where they are together with Princess Diaspro to watch a show at Redfountain in which Sky appears. Before season 1, they paired their son up with Princess Diaspro as his fiancée, but Sky manages to get out of the engagement to be together with Bloom. They don't like her very much until season 2, episode 14, in which she helps save Diaspro.
Princess Diaspro: A member of Eraklyon's nobility and was Sky's fiancée until he met Bloom. She tries to win Sky's affection back by allying with Valtor and having herself nominated as the King's liaison officer of Eraklyon but fails. In Season 6 Princess Diaspro returns after forming an alliance with the Trix but before she could join them she was put up to a test to destroy Bloom for good. In Episode 6 of Season 6 while through all the comotion in Domino's palace she tries to kill Bloom in the vortex of flames, but her plans were halted by Daphne and Sky. During the battle with Daphne she disappears out of now where as her where abouts are unknown.
Prince Thoren: A paladin who is Sky's cousin. Prince Thoren got married to daphne after the Winx Club had defeated Acheron from claiming the ruler of the Magix Universe and being the only person with powers.
Lady is Sky's pet dog. Lady only appears in the 1st season.
Yoshinoya: A powerful man who wants to take control of Eraklyon and it is because of him that Sky and Brandon had to switch identities in Season 1. In Season 2, he kidnapped Diaspro but the Winx saved her.
