Blue Fairy

Reul Ghorm, better known as the Blue Fairy, is a supporting character on Once Upon a Time. She was the leader of the fairies in the fairytale world, and presumably the most powerful creature in all the land, capable of performing the most exquisite enchantments. She was responsible for indirectly instilling in Rumplestiltskin the idea of creating a curse that would transport everyone in her world to a different one, a curse that was later brought forth by the evil Queen Regina. In the real world, the Blue Fairy's counterpart became the Mother Superior, the leader of the local nuns.

Before the Curse
The Blue Fairy is called upon by Baelfire to get help with his father and the curse that has taken over him. The Blue Fairy tells him that his father can never be the way he was but they can go to "a land without magic". She gives him a magic bean, the last of its kind. After Rumplestiltskin refuses to give up his power and ends up leaving Baelfire to go to this world alone, he frantically calls on the Blue Fairy. She tells him that there is no way for him to get to that world without paying a great price, which is giving up this land in exchange for the next, to which she accidentally admits there is a curse but takes pleasure in the fact that he will never be able to pull it off. He then vows to do whatever it takes to get Baelfire back.

The Blue Fairy often helps many people when they wish upon a star. She does this as well, when a young man named Jiminy wishes for help. He had accidentally caused the murder of a boy's parents, and wanted her to bring them back. However, when she appears, she tells him that she cannot bring his parents back. She however explains that she could make it so that he would be able to watch over the boy. At Jiminy's request, she turns him into a cricket and instructs him to watch over the boy, whose name was Geppetto.

Many years later, she is sitting in the clouds when a clumsy fairy named Nova flies up to sit with her. She gives the Blue Fairy a large bag of fairy dust. The Blue Fairy scolds Nova on her clumsiness and warns her that fairy dust was the most powerful substance in the world, because it is fueled magic. Nova agrees and complains that she had thought she would have been a fairy godmother by then. The Blue Fairy laughs, calls Nova a dreamer, and flies away. Many nights later, when Dreamy is going to Firefly Hill to run away with Nova, she, along with the head dwarf named Bossy, intercept him. She tells him that the two do not belong together, and speaks about Nova's dreams to become a fairy godmother. Only if you two were alone, she argues, would you bring untold happiness to the world. Her speech and Bossy's facts convince Dreamy to go to Firefly Hill - not to run away with Nova and explore the world, but to make sure that they could never be together again.

The Blue Fairy and numerous other fairies assisted in the assault on King George's castle in attempt to rescue Prince Charming. This was apparently because of a favor owed to Grumpy.

During Cinderella's pregnancy, the Blue Fairy aided her in a search to keep Rumpelstiltskin from acquiring Cinderella's unborn baby. She created a powerful magical red quill so that Rumpelstiltskin's powers would be frozen if he used it. This plan was successful, and Rumpelstiltskin was taken to his prison in the dwarves' mine.

A few months later, Prince Charming and Snow White discuss how to defeat the Evil Queen's Dark Curse with their allies. Just before everyone votes to going to war, the Blue Fairy flies in with an enchanted tree. She claims that the tree, if fashioned into a vessel, will take one person and whisk them away to another world, so that they could come back for everyone else and save them. The original plan was for Snow White to go inside the tree so that she and her unborn baby would be safe. However, Snow White went into labor the day the wardrobe was finished, and Charming had to put the newborn baby Emma Swan inside instead. The Dark Curse arrives moments after and the Blue Fairy is transported to the small town of Storybrooke in Maine, USA, where she lives under the name of Mother Superior. ("Pilot"/"The Stranger")

Season 1
During the Miners' Day festival, Mother Superior is supervising Astrid, who has been given the responsibility of ordering twelve containers of helium. Instead, Astrid accidentally orders twelve dozen, which uses up all of the nun's spare and rent money. Mother Superior tells Astrid to fix this mess and then reminds her about how Mr. Gold thinks of the nuns, and storms off in a huff, leaving Astrid distraught.

At the convent for the nuns, Mother Superior and August Booth meet up to have a secret discussion. Mr. Gold watches from afar, and when Mother Superior heads back inside the convent, he stops her to talk to her. Mother Superior, instinctively assuming he is there to collect the rent, explains it has already been paid. However, Gold explains that is not his reason for visiting her. He asks her who the man she was just talking to said he was and asks what he wanted. Mother Superior tries to keep the information confidential, but Gold blackmails her into revealing it. Superior explains that he wanted advice and council as he has just come to town after being separated from his father for a long time and he has just now found him. Gold asks if they have reunited yet, but Superior explains they haven't even spoken yet. Gold asks why, so she explains they had a difficult parting. This then all leads Mr. Gold into believing August is actually his son, Baelfire.

Mother Superior is in the Storybrooke Hospital when Henry apparently dies after eating the poisoned apple. She rushes into the room after Emma's kiss wakens him, now remembering her former life as the Blue Fairy, exclaiming that the curse has been broken by True Love's kiss. She then advises Regina to find a place to hide, calling her "your Majesty".

Season 2
After Snow White and Prince Charming are happily reunited with their daughter, Emma Swan and her son Henry, the seven dwarfs begin to question why they weren't transported back to their world and what the purple smoke was. The Blue Fairy approaches them and explains that it magic has returned and backs up this statement by explaining that she can "feel it". Henry asks the Blue Fairy to do something magical, but she tells him it isn't that simple because she has no wand or fairy dust. The Blue Fairy joins a group to find Rumplestiltskin, but on their way they join an angry mob that is headed for Regina's house. They follow them in hopes of saving the evil queen; which they do successfully.

In the town center of Storybrooke, outside the town hall, a crisis center has been set up after the destructive events caused by the Wraith. The Blue Fairy is at the center, helping people in need. As Red makes announcements to people, Blue tells her that things are getting out of control as people are in a panic and they don’t know what to do. Red reassures Blue and tells her Prince Charming is most likely working on a plan. Later, Charming asks Blue if it is possible for there to be a tree in their world, like the one they used to send Emma as a baby. She tells him it is possible for there to be one, but hopeless without fairydust. When Blue attends the meeting at the town hall to hear Charming’s plan, she sees that Regina has regained her magic, so she, among others decide to leave town, but Charming convinces her otherwise.