Aisling

Aisling is one of the two protagonists of the Irish animated film, The Secret Of Kells.

History
Aisling is a fairy with magical abilities. She has lived for over hundreds of years. She occcasionally shape-shifted into a wolf, a salmon or a deer. She has seen many tragedies and beauty thrive in the most fragile of places. An undefined time ago, Crom Cruach killed the rest of her family. Aisling lived alone in the forest surrounding Kells, until Brendan entered the forest in search of ingredients for ink. First, she watched him from a hidden place. Then, as Wolves attacked Brendan, she called them back and talked with the boy. Then she agreed to show him where he could find what he was looking for, but let him promise that he and also Pangur Ban, who was with him, would never again enter the forest. Aisling led Brendan to the top of a huge, old oak, where she told him her name. On the way back she lost Brendan accidentally, finding him near Crom Cruach's dwelling. Despite her warnings not to speak out the god's name, Brendan called Crom several times, still believing that he was not real, what resulted in branches of darkness emerging from the open gate of the cave. Aisling pressed against a statue standing beneath the entrance, making it collapse and blocking the cave.

Later, when Abbot Cellach locked Brendan into his room, Aisling turned Pangur Ban into a spirit-like creature to slip through the keyhole into the tower and free Brendan, which she used a magical song for. After breaking Brendan out of his room, the pair retreat to the forest where Brendan explains to Aisling why he was locked up. After he says that he must retrieve Crom's other eye, a desperate Aisling begs him not to go, saying that Crom will kill him just as he killed her mother and her people. However, Brendan assures Aisling that it is necessary for completeing the book, and that without the eye it will be impossible.

The two then go to Crom's cave where Aisling seemingly sacrifices herself so that Brendan can get in, telling him to complete the book and "turn darkness into light." Aisling is not seen afterwards except in wolf form, saving Brendan and Brother Aidan from the Vikings.

Years later, she guides an adult Brendan back to Kells, seemingly happy that he'd returned.

Centuries later, she makes a brief cameo appearance in Song of the Sea, when Ben and Saoirse board a bus full of Trick-O'-Treaters Aisling could be seen sitting on the left. She does not appear to've aged at all since the time of Kells.

Characteristics
Aisling is a demi-god, the princess of the now destroyed Tuatha Dé Danann, living in the woods outside of Kells. She is a protector of the forest, and doesn't like unwelcome guests. At this point her age is uncertain, but she is likely to be hundreds of years old.

She is very protective of her forest, reacting with hostility to Brendan the first they they met. However, Aisling is also fiercely loyal and supportive once she gets to know and befriend people. She helped Brendan escape his room when his Uncle locked him in for disobeying him, and assisted Brendan in attacking Crom at great peril to herself. So far her only interaction with other characters in the movie is with Brendan and Pangur Ban.

It is also revealed that Aisling can disguise herself into animals such as wolves, deer, and fish. She may be able to become other animals as well, but no evidence of this was shown in the movie. She appears as a salmon in the Origins prequel for Brendan, and appears to be mode-locked to her wolf form by the end of the film. For a short time, however, she appears in her human form when the grown Brendon returns to Kells.