Purah is a character from The Legend of Zelda: Breath of the Wild. Purah is a Sheikah who can be found in the Hateno Ancient Tech Lab of Hateno Village, in the East Necluda region. Despite her appearance, she is actually the elder sister of Impa.
The Great Calamity
During the Great Calamity and the battle against Calamity Ganon, Link was severely injured fighting corrupted Guardians at Fort Hateno, Zelda requested Impa, Robbie, and Purah to protect him. Purah thus took him to the Shrine of Resurrection in order to hide him and heal. After Zelda choose to seal Ganon in Hyrule Castle, Impa, Purah, and Robbie decided to separate to ensure at least one of them would survive to aid Link when he finally awoke. However Purah insisted Robbie escort her to Hateno Village, they eventually made their way to Fort Hateno where they parted company. Purah set up shop in the Hateno Ancient Tech Lab where she worked as director researching Runes to assist Link when he will come back.
Age of Burning Fields
Over the years Purah mentored Nanna and later Jerrin who was sent by Impa to assist Robbie whom she eventually married. At some point, Nanna returned to Kakariko Village settled down and had a family, though later regretted not heeding Purah's ideas and warnings about the dangers of growing old indicating she was aware of Purah's age reversing research. Though most of the villagers in Hateno Village grew to respect her over the years and respectfully refer to her as the Director, they generally do not bother her and even the elders of the village who lived during the Age of Burning Fields are not aware of the nature of her research. Purah used the blue flame from the Sheikah Furnace found in Hateno Village to power her Guidance Stone and laboratory, though would occasionally have to relit her lab's small furnace when the flame went out which became more difficult as she aged. As a result, the people of Hateno Village came to associate the blue flame with the director.
As she got older, Purah began researching an age reversing rune to strengthen the Hyrulean army to fight the inevitable return of Calamity Ganon. Symin was set by Impa to assist her. Purah would later complain about his usefulness in a letter to Robbie. Her research initially proved fruitful as it reversed her age at first to a Sheikah woman in her early fifties. But she feared she might wake up and find herself in the body of an infant. Her age continued to regress to a woman in her thirties then twenties, later to a teenager, and eventually stopped at the age of a six year old girl. She began working on a Rune to reverse the process, but her Guidance Stone ran out of energy, and she was unable to relight the furnace that powered her tech lab. Symin proved to be unsuited to this task, and she was forced to light them herself. A girl in the village saw her, she was thus forcing her to resort to gas powered lights. When Robbie wrote her a letter about sending his son Granté to study under her, she replied not to send anyone, presumably embarrassed by her current state which is reinforced by her by her choosing to keep her condition a secret from even her own family as neither Impa nor Paya are aware of it.
If Link visits the lab before receiving the Locked Mementos quest from Impa, Purah will even pretend that Symin's the lab's director and that she is his assistant.
After seeking out Impa, Link is informed that his Sheikah Slate is missing some of its components and Impa tells him to seek out the director of the Hateno Ancient Tech Lab to get it fixed. Upon arriving at the lab, Purah plays a joke on Link by pretending that Symin is the director, though Symin tells him the truth and Purah reveals herself to be the labs true director. She explains that her current condition is the result of an experiment gone wrong but tells him he should read her diary to learn more about it. She takes a look at Link's Sheikah Slate and is surprised to find it has Remote Bombs, Magnesis Rune, Stasis Rune, and Stasis Runes which Link acquired inside the Shrines located on the Great Plateau, yet lacks standard runes such as the Camera Rune, Album, and Hyrule Compendium. She states she her Guidance Stone can restore the missing components, but first her lab's furnace must be relit with the Blue Flame as her lab is powered by it. Link can find a Torch inside the Lab and can obtain the Blue Flame from the Ancient Furnace inside Hateno Village. He can light special lanterns along the way incase he loses the flame, making it easier to relit if it goes out. Link is unable to light the lanterns or the lab's furnace if it raining. Once Link lights the labs furnace, power is restored to the lab's Travel Gate and Guidance Stone. Purah tells Link to place the Sheikah Slate in the Guidance Stone which restores the missing components and fixes all corrupted data. This unlocks the Camera Rune, Hyrule Compendium, and restores the pictures originally stored in the album. Purah suspects that the images were taken by Princess Zelda when it was in her possession as the pictures are of locations as they appeared before the Great Calamity. Purah suggests he talk to Impa as she was close to Princess Zelda and would likely know more. She also mentions that if Link brings her some ancient parts, she will give him something good and tells him to speak to Robbie at the Akkala Ancient Tech Lab as he has been working on something that might aid him. Interestingly, despite her telling him to read her diary earlier to learn more about her condition and even points out its location, she insists he not read it. If Link reads Purah's diary, she will punish him by taking his Sheikah Slate and seemingly erasing all its components, however when Link checks it, he discovers nothing is missing and Purah reveals she had played another joke on him, even imitating the Guidance Stone's voice to fool him, indicating she really has no problem with Link reading her diary and was simply pranking him, thus explaining her contradictory behavior. Link can also find two manuals written by Purah, the Sheikah Slate Manual and Camera Manual on the table next to her which provide instructions on the Sheikah Slate and Camera Rune respectively.
Slated for Upgrades
If Link asks her about the something good she promised, she explains that in exchange for ancient materials she can power-up Link's runes, such as the Sheikah Sensor for three Ancient Screws, Remote Bombs for three Ancient Shafts, and Stasis for three Ancient Cores. Link can also ask her about Ancient Materials which Purah reveals are what Guardians drop when he defeats them or by examining broken Guardians.
Upgrading the Sheikah Sensor links it to the Hyrule Compendium allowing it to detect the objects Link records in the Hyrule Compendium when he takes pictures of them with the Camera and causes Symin to want to test it by having Link use it to find a Sunshroom behind the lab and take its picture leading to the "Sunshroom Sensing" side quest.
Upgrading the Remote Bombs increases their power while decreasing their recharge time. Upgrading the Stasis Rune allows it to effect enemies.
Link can also ask her about Robbie who she explains is her subordinate who runs the Akkala Ancient Tech Lab and tells Link he should bring Ancient Materials to Robbie as well. This leads to the side quest, "Robbie's Research".
She appears to look like a six years old girl due to using a Rune to reverse her aging that went too far. Interestingly, she is the only member of her family to have inherited the Sheikah's traditional red eye color, as Impa and Paya both have brown eyes. However like her sister and grandniece, she has white hair which she has tied up in a bun. She wears a pair of glasses and a mask with Lizalfos-like eyes on her head which are identical to the ones her subordinate Robbie wears. She wears Sheikah clothing which takes the form of a dress with a frilled skirt and Mary Jane shoes. She wears Sheikah gauntlets and leggings. She wears a backpack like device on her back with what appears to be a flute attacked to it.
She also lacks the Sheikah eye crest tattooed on her forehead like Impa and Paya despite coming from a family with a strong Sheikah lineage as it is customary for Sheikah with such lineage to tattoo the crest or their forehead, though presumably this may be out of vanity or it is concealed by her hair and/or the bandana also concealed under her hair. Additionally it is possible that because Purah studies ancient technology, she it is suggested she doesn't follow Sheikah tradition as faithfully as her sister and grandniece, as the Sheikah had given up much of their ancient technology, while Purah herself embraces and studies it. It may also be due to the fact that Purah is a scientist and may reject such practices as superstition as the Sheikah eye chest is considered a protective talisman.