Author's Note: This is based on a prompt from tumblr's skywardpromptsanonymous. Contains tons of spoilers.
Prompt: What if Ghirahim is not Demise's sword per say, but instead a container or vessel for Demise's sword? When the sword was pulled out of him, his limp body look pretty lifeless afterwards, and Demise immediately starts checking out the sword.
What if Ghirahim was a minor demon that served as an unwilling vessel/hiding place for Demise's cursed sword, and was promised that if Demise would be freed, the sword would be removed from his body in exchange.
Of course he wasn't told that it would kill him.
The great war drew to an end when the humans were in the sky and the land beneath them was swathed in blood and darkness. The final confrontation - the fight that would decide their fate - would be against the goddess, and the odds seemed to be against his master.
The once-vast army of demons - aside from himself, although he was a lesser demon and so low in the hierarchy that it was a miracle he'd even survived for this long - was disappearing in the goddess's wake.
He would be next.
He knew it
But he wasn't ready.
His master approached him one night before that battle, cursed sword in hand.
"Become its vessel. Keep it safe. Bring me back if I am destroyed and I will take it from you.
"This is the only way you can be free. The only way you can continue to live," his master told him. "Continue to serve me and I will keep my promise."
And he accepted.
The pain that bound the sword to his body was blinding, all-consuming. For a moment - though it felt like an eternity - all he could feel was the fire, all he could see was the way it burned and swallowed him whole.
But he emerged from the flames a stronger being. He could feel his master's power flowing through his veins. The others around him seemed to sense it, and they shirked away from him. They obeyed him. They feared him.
For the first time in his existence, he felt confidence.
And it was the greatest feeling he had ever known.
The years piled up behind him. Decades turned to long centuries. He waited patiently, but eagerly. It couldn't be much longer now. The goddess would appear again and he could free his master.
He could free himself.
He wondered, sometimes, how different life would be when he was truly free of this responsibility to his master. He'd experienced bits and pieces of it while he waited for his master's return, when he finally had a chance to walk the land and watch it grow and rebuild in the wake of the great war. The coolness of Faron's woods; the scorching warmth of the towering volcano and its surrounding mountains; the fierce dryness of the desert. It was all so different, all so...beautiful?
But there was still the lingering pain of the sword in his body. He felt it within him, felt its weight and its anger burning just as powerfully as it had all those years ago. It never left him, never stopped. So he tried to channel that pain, made it into a strange sort of motivation to free his master.
Soon, they would both be free.
Soon.
The day finally came when the reincarnated goddess showed herself. He found her and plucked her from the safety of her open skies. He brought her to the surface and hunted her down across the lands he had slowly come to know so well.
So close, so close. He was so close, after all these years, all these decades, all these centuries of forced patience. The heavy pain of his master's cursed sword would soon be gone.
And yet, somehow, he'd forgotten the goddess's promise of her chosen hero.
It was disappointing, really, when he finally met that hero. How could this boy, this pathetic human barely at the cusp of adulthood be the one that the goddess herself chose to defeat his master? The boy would be crushed in seconds, flat as a bug beneath his heel.
But the boy was so persistent. Never gave up, even when he'd been beaten within an inch of his life. Always there, always willing to challenge him.
The boy didn't have power like his, though. No one did, except his master.
And so he remained confident. He toyed with the human hero, using only a fraction of his true power against him.
But, in retrospect, perhaps he was too confident. Perhaps he should have destroyed the boy when he had the chance.
Because, in time, the boy did become that chosen hero.
But the hero was too late, because after all was said and done, the goddess was finally his.
At long last, his master would return to this world. His master would take that wretched sword from his body and he would be free. No longer would he be a vessel with one purpose in life, but his own being.
His own being.
The hero tried to stop him, of course, like the pathetic little guard dog he was. And the hero put up a good fight, he had to admit; but it wasn't enough. In the end, his determination was far stronger than the boy's. His power, his motivation, outweighed that of the goddess's chosen hero.
And that cold, dark night, after so many, many years, his master was finally set free.
But it wasn't meant to be. He should have expected something like this, he knew; you couldn't trust demons. You could never trust them. Especially not their masters.
Those painfully familiar flames exploded in his eyes when his master drew the cursed sword back from his body. There was more pain, more agony than before - but beneath it all was excitement and relief. After this there would be no more pain, no more weight of responsibility. He had served his master to the fullest. Wouldn't that be more than enough?
But then there was darkness, so much darkness. It pressed in around him, enveloped him like those flames. But it wasn't as hot, as painful as they had been.
This was a cold darkness.
A lonely one.
And when it swallowed him whole, there was nothing left. No green forests, no fiery mountains, no vast deserts.
Only emptiness.
The sword wasn't bound to him; it had become his soul. His life. His only purpose for still being alive.
And it wasn't supposed to be this way.