Radius

King Radius is Stella's father and the King of Solaria.

Appearance
Radius has orange-colored hair and eyes. He wears a golden crown that resembles the sun, a red fuzzy hood, golden shoulder plates and a red cape. His sleeves are puffy with an ivory color, as the sleeves passes his elbow it becomes slender and gold. He has a collar shirt with a round golden necklace, belt, puffy pants and above knee ivory-colored boots.

Personality
Although he could be somewhat absent-minded, arrogant and used to a life of deference like his daughter, Radius is a genuinely loving and caring father.

Seasons

 * -|Season 1=

King Radius made his first appearance in Stella's magically-induced nightmare, where he revealed that he is divorcing his wife, Queen Luna.

Later on, Stella finds out that her parents' divorce was no nightmare, but reality. As a result, she lashes out at Bloom during the Day of the Rose as she was still slightly in denial about her parents.

King Radius did not appear in season two, but was briefly mentioned by his daughter.
 * -|Season 2=

King Radius made his second official appearance in Season 3, at Stella's Princess Ball.
 * -|Season 3=

At first, all seemed well: he greets Stella with a loving paternal hug and tells Bloom to dispense with formalities, showing himself to be a genuinely caring father as well as an easy-going yet warmly welcoming host.

However, things took a dark turn at the ball: he revealed that he was to marry Countess Cassandra, who proceeded to put both him and his daughter under a spell: Stella was transformed into a frog-like monster, and Radius' mind came to be completely under Cassandra's control. As a result, he failed to realize that Stella had been placed under an enchantment, and ordered his guards to arrest her, forcing the Winx to flee Solaria.

Later on, at Eraklyon's One Thousandth Anniversary, he was accompanied by Countess Cassandra and her daughter, Chimera, to the party. After the party erupts into chaos when Prince Sky falls under Diaspro's spell, Radius is caught in the battle and abandoned by Cassandra, literally left to the dragons. A dragon catches sight of the vulnerable king and approaches him, poised to attack. Upon seeing this, Stella selflessly rushes to her father's aid (despite his cries to her to save herself), pushing her powers far beyond their usual limits to protect him, resulting in her collapse.

Radius rushed to her, cradling her in his arms and pleaded with her continuously to respond to his cries, but as she remained unresponsive, he starts to cry. Fortunately, Stella's selfless act earns her her Enchantix, and she regains consciousness in her new fairy form (much to the relief and pride of her father and friends). Father and daughter shared another warm embrace before she left with her friends.

Unfortunately for Radius, he again fell under Cassandra's spell, only that this time it was no longer as strong as it had previously been, given his attempts to assert his will against her mind-control: he protested against her caging his doves and calling them "pests", begrudgingly agrees to banning Stella from attending their wedding, and later confesses that he was uncertain of exactly what he was doing. When the Winx learned of the wedding, they sabotaged it by revealing Cassandra's and Chimera's schemes to take over Solaria to everyone present at the event, and fought off the guards who tried to stop them. Stella uses her fairy dust to break Cassandra's spell over her father, and reuniting herself - joyfully - with her equally-relieved father.

King Radius appeared in The Pillar of Light. Where he fell ill due to Tritannus taking the seal from the Pillar of Light. He also appears to hare a harsher and more arrogant behavior, especially towards his ex-wife, Luna.
 * -|Season 5=

During the eclipse, he went to the room where Second Sun of Solaria was kept, in order to stay alright. Luna got worried about him and came to see him. Radius was not happy to see her, but before he could drive her away, he fainted and fell ill. Luna took him to his bed and took care of him. Stella got worried about Radius as well and was surprised to see her mother taking care of him. Out of worry, Stella leaves for the Infinite Ocean in hurry.

Stella soon manages to restore the Pillar of Light, but got another thing to worry: as Radius was alright, that would mean that her parents will start fighting again. At the throne room Radius and Luna welcomes Stella back. Stella tries to get her parents get along by saying that she thought of what both of them would have done and putted them together. Radius however ignores this, seeing what Stella means. Luna gets angry at him and they start fighting, resulting in Luna leaving the palace and Radius preparing to meet with Faragonda in anger.

Radius speaks with Faragonda, Teredor, Oritel and Erendor. They did not agree with each others plans, so Oritel tells that they should convene a summit and meet up in Domino's castle.

Shortly after Radius meets Stella and Luna having already tired of his lawsuit between them and invites her fashion show. These react with enthusiasm and behind Stella still angry. In Exhibion Radius and Luna took very bian thanks to wish Sirenix her daughter so that the two aid in the final battles of the season.

Appears in "Queen for a Day" when it promotes his own daughter as queen for just one day. First Winx allows access to the Library of Solaria and then leaves behind a gentlemen seeking help. After Stella abused his powers by creating a party queen and makes some changes to the guards, especially Brandon was going to meet with Stella bothered by what happened and Radius can do nothing to reassure the range of his daughter.
 * -|Season 6=

In a few moments, Radius is surprised to see that change your attitude Stella (due to the Magical Mirror) and bring to five witches to attack Winx in Solaria and also ordered the guards to let them fight. But all ends when her daughter possessed enchants even his own father leaving him without speaking. Bloom protects your shield while Winx struggle with the Witches, and Stella had to go to Legendarium after this incident.

Movies
He is briefly seen in the ballroom on Domino celebrating the revival of the planet, talking with his ex-wife, Luna, and his daughter, Stella. However, he does not dance with Luna. He has no speaking role there.
 * -|The Secret of the Lost Kingdom=

Trivia

 * The word "Radius" means "ray" in Latin, and was probably the name given to Stella's father as reference to a ray of sunlight, Radius being shown to be associated with the Sun, proof that he can't survive without the sun of Solaria if the Pillar of Light is damaged.
 * His outfit since his first appearance as an illusion is similar with Oritel outfit.
 * Along with Ligea, Galatea and Miele were the four characters where Winx saved to earn their Enchantix.
 * In Season 3 Episode 8, When Cassandra leaves Radius is that since neither was possessed. Perhaps her spell was not very powerful.
 * Interestingly, Radius is the only King who has suffered extensive damage in seasons.