Erendor/Series

Pre-Series
Erendor was to protect planet Domino until King Oritel and Queen Marion returned.

Season 1
Erendor played only a small part in season 1, but his part was especially important to the story line. He was featured in episode seventeen, "Secrets Within Secrets" as a VIP guest for Red Fountain's Exhibition along with his wife and queen, Samara. It was Erendor who revealed that Brandon and Sky had switched places, a revelation that shocked the Winx completely and caused Bloom to go to Gardenia, where the Trix stole her powers.

Season 2
King Erendor appears with Queen Samara in the fourteenth episode, "Battle on Planet Eraklyon", where Sky introduces Bloom to his parents. However, Erendor called for Sky to tell him that Diaspro has been kidnapped in pursuit for large ransom from the royal family. Erendor urges for his help, even though Sky nullified his engagement to Diaspro; making it clear that both he and Samara still regarded Diaspro fit for Sky, and not Bloom. While Sky, Bloom, Flora and Brandon go rescue the princess, Erendor thought his son might in fact find love for Diaspro after all. In the end, Erendor and Samara misjudged Bloom and accepted her.

Season 3
In the eight episode, "A Disloyal Adversary", King Erendor and Queen Samara attended the Millennium celebration of their planet, Eraklyon. He and his wife watch as Sky and Bloom danced. He then watches Sky make a big announcement to the people of their planet. When Sky announced that Diaspro was his girlfriend, Erendor did not question it. After Diaspro falsely accused the Winx as Valtor's minions and the dragons were released, Erendor quickly tried to lead his people to safety.

In the next episode, "The Heart and the Sword", he announces Sky's engagement to Diaspro to their people.

Season 4
Erendor was seen going to Gardenia, looking for Sky to fulfill his duties as the new king of Eraklyon. He tried to buy Eraklyon's royal seal back with Eraklyon money, which the salesman thought was a joke. Many people on Earth laughed at his appearance and clothes as they were not familiar with the Magic Dimension's clothing.

Season 5
In "The Sirenix Book", he called Sky to checkup on him.

Erendor appeared after Tritannus stole seal from Pillar of Light. This caused him to meet up with Faragonda, Oritel, Radius and Teredor. He strictly stated that all of the worlds should defend themselves rather than unite, but he still agreed to meet with all the other royalties on Domino. Wondering where Sky was, he promoted Diaspro to get Sky from Magix.

During the meeting he did not changed his mind about Eraklyon defending itself, causing Zenith's and Linphea's royalties to think the same thing. His opinions caused Radius to change his mind too, since Solaria would have united if the other worlds would too. Sky tried to speak sense to him, but Bloom's and Diaspro's interference made it impossible. When Tritannus stole the seal from the Pillar of Balance, he caused the balance of the magical dimension to literally collapse, all of the royals had to return to their worlds to defend their people.

Back on Eraklyon, Sky still tries to convince his father to return back to Domino to form a union, but Bloom called Sky, making Erendor even angrier as he has had enough of interferences, but his wife told Erendor to give it a rest and to let Sky answer, although Bloom stopped the call on the final second.

Although it took some time, Sky was finally able to convince Erendor that the best way to defeat Tritannus was to cooperate with others. He praised Sky for his actions and that he was proud of him as they prepared themselves to defend Paradise Bay that was currently under attack by Tritannus and his pollution. Outraged by Sky's alliance, Diaspro stepped in and argued that it is to dangerous for a prince and proceeded to take him back only to be rejected. Upon seeing this behavior, Erendor renounced Diaspro's position as liaison and watched her storm off and fall into the pool.

He is then seen with the rest of his family and fellow sovereigns at Andros, celebrating Tritannus' defeat.

Season 8
In "The Wishing Star", at the royal palace, Sky and his father have an argument about the issue of Sky's presence in Eraklyon in the Court room, to which Sky storms off, much to the chagrin of his father who wants him to spend more time in the royal court as the crown prince, opposing Sky's personal aspirations to be a professional hero.

The Secret of the Lost Kingdom
It seems that he was not really in bad terms with Oritel at some extent even before making up for his betrayal since he can be seen dancing in the end of The Secret of the Lost Kingdom at the celebrations of Domino's rebirth, probably because his guilt had not yet started troubling him like in Magical Adventure.

Magical Adventure
In the second movie, it is revealed that Erendor is tortured by his guilt for a mistake he made years earlier: before the destruction of Domino he was the friend of Oritel, Bloom's birth father, and an ally of the Company of Light, and he promised Oritel that he would protect Domino from the Ancestresses until the Company of Light returned.

But he betrayed them when the Ancestral Witches destroyed the most magnificent city of Eraklyon, Havram, and told him that they would spare the rest of Eraklyon if he let them destroy Domino. Having no other choice, he made a deal with the witches according to which he decided not to help his friend and in exchange, they gave him a magical hourglass containing pollen from the Tree of Life which would protect Eraklyon from Evil.

Since then the City of Havram in Eraklyon has been full of wandering shadows. He later regretted this bitterly and destroys the hourglass at Havram by throwing it on the ground but while the hourglass itself was broken, the pollen it contained gave birth to a sapling of the Tree of Life.

At the end of the movie, he made up for his betrayal of Domino by protecting Bloom from one of Belladonna's attacks. Doing so nearly cost him his life, but his sacrifice and Oritel's selflessness during the battle with the Trix and the Ancestresses helped restore the Good Magic again after the Good Magic freed from the sapling begun to fade away since sacrifice and selflessness were two sources of good Magic.

In the end, he reconciled with Oritel and happily accepted his son's decision to marry Oritel's daughter, Bloom.

Revenge of the Trix
He reprises his minor role as he observes the Exhibition at Red Fountain. However, in the special he leaves because of the ridiculous battle between Bloom and Diaspro.