Hylia always lived by her own self-enforced rules. Obey the wishes of her older sisters, the Golden Trio. Protect the Triforce from all who would use it with evil intent. Show compassion for humanity and all beings on the Goddesses' earth. Interact with the Hylians only when needed and stay aloof when not.
But then Demise appeared. With his horde of monsters, he tore through the Goddesses' people to try and get the Triforce. Hylia could not allow the death and destruction to continue. She looked into the hearts of men until she found one with an unbreakable spirit. To Link, she bestowed a sword that she had forged to counter Demise's Ghirahim. But as soon as he grasped the sword in his hands, Hylia saw that he would die.
The death of one mortal should not have shaken her so, but the thought of losing Link rocked her to her core. She tried to find another way, another path that would not end in her champion's death, but her struggles were in vain. Knowing this inevitable outcome, Hylia was determined to not let Link's death be for nothing. His strength was such that he could hold Demise off long enough to allow the rest of the Hylians to escape with the Triforce. Hylia would use her power to send her people into the sky then seal Demise away. It wouldn't be enough, she knew. She would exert too much power sending the people into the sky to seal Demise for long. She would have to sacrifice her immortal body and return as a mortal to strengthen the seal. With her trusted servant Impa's help, it should be enough to protect her people even when they return to the surface.
The time had come to execute her plan. Link went off to face Demise while Hylia lifted great chunks of earth into the sky. Once her people were safe, she went to confront Demise. To her surprise, Link was still alive. The sheer determination of Hylians never ceased to amaze her.
"Lend me your power for a few more precious seconds," she called to him. "We can seal his power and protect those in the sky."
"As you wish, Your Grace," he yelled as he redoubled his attacks.
Hylia conjured a sealing spike pouring all of her power into it. But then a gut wrenching cry filled the clearing. Hylia looked up to see Demise's sword plunged into Link's stomach.
"NO!" she screamed. A wave of magic rolled through the clearing, and the sealing spike was hurled into Demise's head.
The demon only laughed.
"Your energy is weak, Goddess," he spat at her. "And your reliance on mortals will fall short just as your champion did. I will arise to get the Triforce. I will succeed!"
He laughed maniacally, even as his form was reduced to nothing but an oversized, scaly being and he was imprisoned.
Hylia ran to Link's side. He was still breathing, though raggedly, and for the first time in millennia, Hylia wept.
"Because of your courage, our people are safe," she said to him. "I am proud of you."
"To earn a Goddess' praise," Link smiled despite his pain, "is more than I could ever ask for."
His eyes closed, and a rush of feeling overcame Hylia.
"Your spirit cannot die here," she whispered. "Your courage will live on, even as I shed my immortal body. May you forgive me for extending your battle, but I cannot reincarnate in this world without your unbreakable spirit to inspire me."
She leaned down to kiss Link's forehead, and closed her eyes as she felt all of her power leave her.
Zelda opened her eyes. The wind had been knocked out of her when Pipit pushed her over during their play-fighting. Link was now brandishing his stick-sword at Pipit.
"You will not harm the Goddess Hylia," he cried with childish righteous fury. "I will slay you, evil demon."
"Do your worst, mortal champion," Pipit yelled back before swinging his own tree branch turned sword at Link.
Zelda stood up, trying to find where her own stick-sword had been tossed off to. Pipit was overwhelming Link, and Zelda couldn't come to his aid fast enough. Pipit pantomimed striking Link multiple times, and Link fell to the ground.
"No, don't hurt him," Zelda cried as she finally found her sword. She barreled toward Pipit and whacked him with it a few times for good measure. "I seal you away, evil demon, for the good of my people in the sky."
"No, my power!" Pipit cried as he fell to the ground dramatically. "Curse you, Hylia, and curse your people, too!"
Zelda giggled at Pipit's theatrics and turned to race to Link's side.
"What are you doing?" he whispered, cracking one eye open to look at her.
"Hylia saves her champion with her love," she explained.
"That's not a part of the story," Pipit called, sitting up from his sprawled position.
"Well it should be," Zelda yelled back. "He died for her. Why wouldn't she love him?"
"Because she is a Goddess, and the hero was just a hero," Pipit argued. "He died honorably protecting the Hylians, and that's the story. Don't go changing it."
Pipit left in a huff, leaving Zelda kneeling over Link.
"I like your version better," Link said as if that settled the matter. He sat up and brushed some of the dirt off his pants. "Besides, it means Pipit doesn't really beat me up all the time."
Zelda giggled and grabbed his hand, "Good, now let's go play some more."