High Priestess of the Gerudo
Mamuuru is, in a word, arrogant. In three words, she's arrogant, mistrustful and cynical. But she's also compassionate, rational and noble, and for there isn't any greater desire in her heart than the freedom and well-being of her beloved Gerudo tribe. And that preoccupation is going to get her in trouble one of these days, because the first thing that one needs to know about Mamuuru, High Priestess of the Gerudo, Great Lord in the Black Legion and great heroine in the war against the Sacred Alliance, is that she doesn't like His Steward a great deal. Furthermore, she wasn't particularly fond of Ganondorf, doesn't really have anything against the Races of the Light or the Sacred Alliance and lacks any specific desire to escape the desert of her upbringing and go and live forever in the dismal, soggy Northern Lands. In fact, she loves the desert. Or at least loves it like a child loves a borderline-abusive mother who pushes them into daily gymnastics training despite the fact they'd rather be drawing ponies. She understands, perhaps better than anyone, that it is the desert that makes the Gerudo what they are. When His Steward came to her people and promised them that he would give them the Northern Realms to live in if they just raised their scimitars and fought for him, Mamuuru almost wept to see how enthusiastically her people cheered. Did they not see, as she did, that it was the desert that was their birthright? Didn't they care that without the desert they'd just be pasty, pointy-eared Hylians with farms and husbands and tiny, ineffectual noses?
So Mamuuru is unhappy with His Steward, although she dare not voice this opinion to her people. Mamuuru was unhappy when her mother told her that the reason she wasn't ruler of the Gerudo was because a man had been born and stolen her birthright away, and Mamuuru is certainly not happy that, now that she has gained her rightful place as the ruler of the Gerudo, another man (presumably, hard to tell with that cloak) has come along and swept her tribe up into another war against a people that Mamuuru barely hates at all. (She even quite likes the Gorons, with their lovely round faces.)
But the High Priestess is nothing if not aware of her flaws, minimal though they may be. She knows that her people are only semi-in her favour right now, and she knows that any unwise declarations of disdain for His Wonderful Steward will only worsen her hold over the Gerudo tribe. She knows that she must bide her time, keep her feelings in check, and do what is best for the Gerudo tribe the most difficult way of all, by grinning and bearing it. Grinning and bearing it while her sisters are sent off to die in meaningless attacks on Hylian soil. Grinning and bearing it while her tribe stop worshipping the desert in favour of new goddesses like Zora jewellery and indoor plumbing and flower gardens. Grinning and bearing it while a man in a mask and a hooded cloak floats above them all with his unknowable motives, and calculates endlessly while the numbers die beneath his feet with throats full of blood and unspoken dreams.
To be honest, Mamuuru hasn't ever really grinned. But still she bears it. And it is a terrible weight that she bears.
Mamuuru's equipment is pretty minimal. As every individual living in the wilderness does, she carries a basic knife for general purposes, but very seldom uses it in combat. Her only two real tools and weapons are her body and her mind. Where "mind" also includes her magical prowess.
What she does wear, however, is a relic known as the "Desert Diadem", inherited from her mother after her death. Returned to her by a Gerudo warrior who had no comprehension of its power, the Diadem has sat upon her brow ever since. An ancient artefact of unknown origin, it is wrought of yellow gold and misty rubies. Although the true extent of its powers are unknown, it is believed to enhance the range and intensity of her Spirit Magics exponentially. Whether Mamuuru guards it so jealously for this reason or because it is a memento of her beloved mother is unclear.
Mamuuru's mother was the great High Priestess Kanja, who ruled the Gerudo for several year before the birth of the Thief King Ganon and his ascent to power as a young man. Kanja even had a part in raising Ganondorf, although after the death of his mother in childbirth he was mainly raised by his two aunts, Kotake and Koume. She did not resent them for this, however, as despite Gerudo tradition the High Priestess always favoured her own daughter, raising Mamuuru in many ways as though she expected her to inherit the tribe's leadership some day. Naturally, one day she did.
Mamuuru's mother died during the War of the Triforce. After the fall of Ganon, Kanja, who had predicted such an eventual result, led her people on a pre-determined escape route from Hyrule, South over the Bridge of Falling Sands. Witness accounts from the day vary, but all agree that the vengeful forces of the Northern Realms were in pursuit of her people, and Kanja elected to take the role of rear guard. No-one saw her fall in battle, but her body was later recovered from the shore of Murk River, indicating that she fell down Cucco Canyon, or her body was cast down there and then floated downstream. Her mother's death was a moment of clarity in Mamuuru's life. Kanja had been perhaps the only living being that the young woman had held in higher esteem than herself, and for her to have died in a war about which the both of them had been skeptical from the beginning was mind-boggling for Mamuuru. Not a day after the Gerudo people had escaped to their erstwhile hideouts, Kotake (her sister Koume slain during the War of the Triforce) appeared once more at the Desert Colossus, cursing her people for abandoning the cause so quickly, blaming them for the death of their "Great Leader" and inciting them to vengeance against the Northern Lands. It was more than Mamuuru could bear. It was then that she made her stand, declaring herself descendant of the last High Priestess and thus more likely candidate for Gerudo leadership, and announcing that as of the beginning of her rule the Gerudo conflict with the people of the Northern Lands was over.
It was a risky move, but not a mistake. Whether it was simply because they needed to lick their wounds, or rather because they had become entirely disillusioned by the events of Ganondorf's reign, the Gerudo sided with her in her desire to return to the older, simpler ways. Kotake swiftly went from incensed to accommodating, offering her age and wisdom as an advisor to Mamuuru's position. Not wanting to appear uncompromising, Mamuuru assented. Perhaps doing that, and not opting to drive Kotake from their midst at that key moment, was a mistake.
When His Steward came to her at the Desert Colossus and promised her people the Northern Realms once more in exchange for their loyalty, it was a mistake that cost her. But for Kotake, who the High Priestess suspected may have conspired with the mysterious Steward prior to his appearance before her people, Mamuuru might have denied him the Gerudo people's loyalty and changed the course of events significantly. But the witch played devil's advocate for the hidden desires of the Gerudo people, desires that Mamuuru thought had disappeared with the ending of the War of the Triforce. With her people cheering for righteous war against the arrogant peoples of the North, Mamuuru was forced to bow to their desires, and thus the Gerudo people entered a new age of violence.
In a way, Mamuuru blames herself for what has come about. But she has not given in to despair, and despite how she comports herself she still works towards the liberation of her people from the Black Legion. She makes her moves in secret, building up her ranks of like-minded subordinates and allies, and making connections to those with whom an alliance would be mutually beneficial. And she prepares herself for the move that might deliver her tribe from evil, tear them from her grasp entirely, or rip them down the centre like a bird's carcass between moblins. Of the latter two, Mamuuru is sometimes unsure of which would be worse.