To get this started, a foreword. You may or may not have heard of the other universes out there, where the Ghirahim in question is male. There is a reason why, or why not, but I am not sure, it is not my job to question fate, it never was.
"Ghera! Oh, Ghera!" Her name was shrieked at her by one of the servants she worked with. Her mother was in charge of the household, and it was unfair to the other servants that the missus treated her daughter a lot less harshly than the other servants, so Ghera decided that she would give the others a break and take up some extra chores.
"Coming!" She called back, tying long white hair up with a strip of cloth, her bangs falling over her left eye, hiding the lighter eye from view. A flaw she despised in her appearance.
Even though she was a servant girl, she wished with all of her heart a knight would come and steal her away into the night, but that was unlikely, as who could even come to love such a filthy thing like her.
She answered the call, and cried out as she saw the limp body of her mother. Her chest was mauled and bloodied, and she squeezed her eyes shut. Metal pressed into her neck and eyes opened in shock as warmth trickled down her neck.
"Your master is dead, and I never was loyal to him or your mother! And you are filth that should be blotted out from this world!"
She growled, flinging her elbow back and the demon holding the blade to her pale neck coughed, and the grip slackened.
The demon servant took off, bare feet slapping the ground as she tore out of the mansion and into the streets, one hand around her neck to stop the bleeding.
No one wanted her anymore, and she might as well disappear.
So Ghera did.
Death was a welcome friend to her, yet he never gave her that blissful kiss to take her away from her nightmare of a living hell. Her clothing was torn and dirtied, and Ghera could not wash her clothing, nor herself.
Blood stained her skirt from the last time her body made that lovely little cycle nature gave woman so they could be fertile. She stunk and was in need of care...
Hands lifted her up just as she blacked out, thinking death had come for her.
When Ghera woke up, she lay on a plush bed, her clothing taken away, but a pile of loose, fresh clothing lay at the foot of the bed.
She had been given a bath, her hair hung neatly in front of her face in a silvery curtain. She grabbed the clothing and pulled it on, finding that the simple top and skirt was pleasant.
"Are you in need of a new life?" A gruff voice sounded from a corner of the room and she looked up. A male demon who stood as tall as her former master, or even taller, eyes bright red, and hair that flickered like flames moving atop his head. His visage was smashed in and blunt, looking like a breed of dog humans kept as pets.
"Yes..." Ghera murmured, looking down.
"Then become my servant. You shall become a very powerful demon, and you will become a very unique one at that." Ghera looked up, eyes wide.
"Who are you, may I inquire?" She frowned and asked him, standing up.
"The Demon King, Demise." He answered, and her eyes widened, and the servant bowed.
"Why did you pick me?"
"I am in need of a weapon, and that weapon would need all ties to family severed. A girl on the streets dressed the way you were would be perfect."
"I shall become your servant. It is more promising for my future than what I was previously."
When she stood up, her face burned and the Demon King tossed a small object to her. She caught it and looked at the item.
"Put that on, and meet me in the throne room." He turned and left the room.
Ghera shrugged, thinking she had nothing to lose. She put the earring on and collapsed again.
Long silver hair pooled on the floor around her, and she felt different, and stronger, but her hearing was muted slightly in one ear for some strange reason.
The demoness pushed herself to her feet and wandered away, searching for a mirror.
New life, new self.
She looked over her face, her body unchanged by much, if you counted the flat chest being a little more endowed, even though her breasts were now slight, nothing like her mother's lovely ones. She discovered with horror that her left ear was now rounded, and when she brushed a finger along the curve, it was extremely sensitive to boot. The demon located a dagger from a nearby servant who had managed to have a little too much booze the night prior, and she hacked her hair short, leaving a curtain over her left ear and the left side of her face.
And with that, she went to find the throne room.
"What is your name?" The Demon King asked her. "I never got it."
"Gh... Ghirahim." She announced, wanting to leave the woman she was behind her and continue as a new person.
"Ghirahim... You are now my second in command and Demon Lady of any world I conquer."
She bowed. "Yes, my lord."
"Now, there is a matter concerning my weapon..."
Ghirahim turned away, keeping her sword away from the master who turned abusive the moment he laid his scaly hands on her. He hadn't forced himself on her yet, but there was a chance he would order her into his bed sooner or later. Time passed, and eventually, he saw her master's fall, but he had ordered her to revive him when the Goddess Hylia was reincarnated in mortal form.
And so, in fear of his anger, the demon who had faced a few millennia with his constant threat, she took up the order, and Ghirahim did not look back.