He is a loving and caring father to his daughter, and sometimes stern. He is also very strict about following rules. For example, he refused to give one Crystallite to Gwyllion, because he assumed that there perhaps would not be enough for his own subjects if he gave any to those not from Shimmervale.
He is skeptical towards Mariposa, because she is a Butterfly Fairy, and believes many untrue things about them just as his people do, which is similar to Butterfly Fairies because they also believed many things untrue about Crystal Fairies. He doesn't have a first good impression of Mariposa, but his daughter quickly becomes her friend.
Despite this, he is a humble king, and near the end of the film admits his mistake for misjudging Mariposa, thus apologizing for his accusation against her that she stole a crystal necklace, which was actually given to her by Princess Catania.
After Mariposa and Catania stopped Gwyllion from turning every Crystallite into a hard rock, and after she is forgiven, he became open-minded and willingly made peace with the Butterfly Fairies.
He is first introduced shouting to his daughter, Catania, to stay away from the window, although Catania had already greeted Mariposa and introduced herself. Catania obeyed her father's order, waved goodbye to Mariposa and closed the window's door. He is first seen when Mariposa goes with Talayla to meet the King of Shimmervale. When Mariposa sees Catania again, Mariposa said "hey" and this outraged the King who mistook it for a rude greeting, but Catania quickly said that it is a sign of great respect. King Regelius quickly understood and greets her the same way as she does.
Suddenly, Zee appears and Anu growls at her and Zee growls back. This confused the King who asks Catania if Zee is growling at him. Catania replied that it is also a sign of respect. The King Regelius softened up and greets Zee with growling, making Zee shocked and she thinks the King is crazy.
Then he invites Mariposa to a royal tea. Mariposa embarassed herself because of her big wings that create disasters from every movement she makes. This makes the King asks Mariposa to sit farther until she reaches the outside line of the balcony. Then when the King tried to enjoy his tea with peace, he got hit by a cake which is thrown by Anu to Zee but Zee blocks it and hits King Regelius' face. This frustated the King who said "this royal tea is over," then stormed away.
On the next day, King Regelius accompany Mariposa to introduce herself to the people of Shimmervelle. On the way there King Regelius mentioned that the butterfly fairies are trained in combat skills-hand to hand to fight the Skeezites. To which Mariposa said it never occured to her because she got help from Rayna, Rayla, Zinzie and the mermaid people.
This make the King impatient mistaking that Mariposa does not want to reveal the secret thus saying "If you don't want to tell me just say so". Mariposa apologizes sincerely and said not try to be abesive but this angered the King and looked away from Mariposa.
When they arrived at Shimmervale city, the place is deserted because everyone is staying in their house hiding from Mariposa. This make Mariposa sad and the King try to cheer her by saying that his subjects is preoccupied but one of the people say shouts they are actually not. When Mariposa turned away to leave, her wings hit King Regelius' crown and fall down.
Mariposa hurriedly try to catch it and not noticing her bag snatch the King's arms thus both of them lost balance and fall down making the people mistaking Mariposa attacking the King. Mariposa apologize again and give back the crown to King Regelius and he flew away after stating Mariposa beat the Skeezites by tripping them.
Later, King Regelius is teaching his daughter on battle tactics on how to position the soldiers for defence but Catania did not listen because she is reading books. Suddenly Mariposa come in and thanks King Regelius for the invitation to the ball and asked if she can address the people of Shimmervale. King Regelius frustated when he sees Mariposa and reluctantly agree for Mariposa address to his people.
When Zee try to catch Anu to revenge on him, Mariposa try to stop Zee but end up destroying the mini figure of Shimmervale Kingdom by slamming her hand into it. This angered the King even more and shout. Mariposa try to clean the mess but her wings flap and distract the King cleaning the mess. The King asked Mariposa if she can do anyting about her wings because it's a menace. Mariposa tried to flip her wings into a skirt and King Regelius satisifed and asked her to kept it that way.
While Catania explain about her pasts, we see King Regelius having a picnic with Catania. Then both of them saw Gwyllion who search around in the ground. King Regelius asked Catania to stay in the tower and asked his guards to follow him. He confronts Gwyllion and when Gwyllion asked for one crystallites he declice because his responsibilities is taking care of the crystal fairies.
This angered Gwyllion and she freeze him. When Catania came to rescue, King Regelius shout to go back but it's too late because Gwyllion capture her for hostage. However, King Regelius manage to break free from Gwyllion weak spell and save his daughter from falling even though Catania brokes her wings.
Afterwards, the king appear stroding in the ballroom and when he sees his subjects make complains to Mariposa stealing the crystal which is actually given by Catania. He shouts loudly to calm the people and accuse Mariposa stealing it even though Catania tells her she give it to Mariposa in GlowWater Falls. Hearing that, King Regelius angry at Catania not going there unprotected and order Mariposa to leave believing she gives a bad influence to her daughter and cause enough ruckus.
Mariposa leave Shimmervale after she give the crystal necklace to Catania and this angered Catania to her father thus making her leave the party. Afterwards, King Regelius assured his people that the butterfly fairy threat is gone and go back partying.
While people is having good time in the party, the King is outside the balcony thinking of what he did. Then he sees the Crystallites turn to stones and realize who cause it. Then King Regelius get freeze by Gwyllion's spell and begs mercy from Gwyllion and spare his people and himself.
After Catania and Mariposa defeat Gwyllion, breaking her staff, King Regelius walk outside and sees his daughter transform. He compliments on how beautiful Catania's wing is and proud of her. He also apologize to Mariposa for misjudging her. Afterwards, he confronts weak Gwyllion and prepare to punish her. But Catania interrupts and remind her what the cause of it. King Regellius asked for suggestion from Catania and Catania do what he should do long ago: giving crystalite to Gwyllion. Gwyllion is soften by Catania's kindness and transformed into a kind old woman.
King Regillius is surprised and said that Catania is wiser than him in some ways even though she is still a child. King Regelius asked Mariposa how to repay her deeds and Mariposa said there is one thing he could do for her.
The next scene, shows a party in Flutterfield and King Regellius greets the Queen of Flutterfield formally but then remember what custome Mariposa had shown in Shimmervelle. So King Regellius said "hey" while waving with arms. This confused and startled Queen Marabella towards King Regellius' action but managed to restrain emotion and say "hey" return. Then he represent a crystal necklace to Queen Marabella and the Queen compliments how beautiful it is. King Regelius asked permission to dance with Queen Marabella and she agreed.
- "'Hey!?' Is that how you address the Princess of Shimmervale?"
- "This royal tea is over!"
- "Better. Keep them that way."
- "Not if I can handle it."
- "Give me back my daughter!"
- "Catania!" (seeing that his daughter had smashed her wings against a tree and is continuing to fall down)
- "Catania! You're flying! And your wings are beautiful!"
Quotes: "The most beautiful thing you can be is yourself." | "The best way to make a friend is to be a friend."
Characters: Anemone | Anu | Bibble | Boris | Coral | Dizzle | Elina | Fairy Speck | Flutterpixie | Gwyllion | Henna | King Regellius| Lord Gastrous | Mariposa | Prince Carlos | Princess Catania | Queen Marabella | Rayla | Rayna | Skeezite | Talayla | Willa | Zee | Zinzie
Events: Crystal Ball