In another time...
Demons were many things. Liars, sadists, murderers, rapists, general incarnations of evil, etc. But if there was one redeeming quality they hung to, even if only so their disorganized chaos could be more effective in the suffering of the surface dwellers, it was that they kept their word.
Not that it meant much to anyone. Demons also specialized in loopholes.
So when a group of humans offered a desperate sacrifice of one of their own to open a contract with the demons, there was no reason to expect anything new. Usually, the demon king would have sent a lower caliber demon to deal with something obviously inane (please let our crops grow well and, oh, kill that neighboring village, they suck). But the description of the sacrifice stood out. Not an animal, virgin, child, infant, or even a criminal.
This little, out of the way village that specialized in weather prediction claimed to be offering a young goddess.
When this reached the king, as well as his three sons, all hell rang with their laughter.
The gods did not exist. Well, they might as well not, not since they had abandoned this poor world to its sinful ways near the beginning of its time, or rather, somewhere around the time they figured out the flooding of the world and breeding from a strand of good human didn't fix the problem. The Great Deity had simply built humans with an ingrain fault, for reasons that everyone knew, but few understood.
Since the surface had been rather quiet due to Meliodas, the eldest, had turned in from active duty to train to take his father's throne (which may never happen), the king decided to let said son observe the proceedings and make the contract, just for humor's sake. And, in the off chance they had somehow gotten a goddess, the eldest was the most prepared to deal with it. He needed a break of fresh air anyways.
So Meliodas rose up from the dank underworld to the weather village, invisible until he decided to be seen.
The usual ratty, scrawny savages dressed in sackcloth clothes met him. Pyres on either side. The demonic symbol burnt into the ground near a still pond thick with mosquitoes and scum.
In this way, they made a dark, dank framing to the burst of molten silver and white curled at their feet.
Curious to see what kind of human they had found to dress in precious white cloth, Meliodas drifted near, unbeknownst to the chanting, haggard priests.
"…oh great darkness who rules the deep, the bottomless, the shadow and fire, we offer unto you for a contract of prosperity—"
His feet, covered in shadow and clawed, touched down on damp soil that did not betray his print. He ducked down to peer through the messy curtain of peculiar, silver hair, when the girl suddenly turned her head to stare right at him.
One eye a brilliant blue. The other a bright gold, the pupil imprinted into a holy symbol he only remembered from his youth.
For indefinable expanse of time, they stared at each other. Once he realized he was holding his breath, he slowly breathed in and crouched down, still uncertain to what he was seeing, and it had been millennia since he'd had to question his own senses.
She was nearly as white as the linen dress they had adorned her in. Bruises marred her face, and her hands had been tied behind her back, where a bunch of white, rather ragged feathers massed. Wondering if they were just swan wings (some humans had tried that once), he reached out, ignoring her cringe, to pluck at the feathers. But rather than come loose with the smell of old, dead blood, a small, messy wing rose from her back, weak, crooked, and limp. Broken.
He eyed where the wing met the flesh of her back. All the while, her multi-colored eyes took him in as well.
"—oh great darkness-!" howled the priest.
"That's well enough," said Meliodas, allowing his voice, along with his presence, to be known. Like a tight belt had been removed, his pressing, cold aura dropped out, covering the congregations, snuffing out the stars and moonlight, and turning their pitiful flames into pale, yellow tongues of what they had been before.
He lifted the girl's other wing. Also broken, and in two places. Only then did he take note of the pain his action caused her.
This wasn't a god. No god would have been cowed and broken by mere mortals. Nor would a god allow their heavenly body to be so broken and pathetic, or rather, their bodies wouldn't be able to be such. If his memory served right, a god's body was like refined fire and diamond, which, in a god's natural state, radiated light like unto a sun.
But this broken, mutated thing didn't glow. She had dried blood on her cracked lips and her crippled wings wouldn't have lifted a toddler.
He reached out his senses towards her, looking for the falsehood. He was a demon, falsehood was his business. But even as he verified the tendons and blood connecting her wings to her body, he felt the light warmth, like a dream, buried beneath her flesh. Even as it stung his nose, nostalgia washed over him. Yes. This was something of his youth, when heaven still stood.
"Where did you find her?" he asked the human, who flinched rather comically on meeting the bottomless depths of his black gaze.
"She wandered in with an injured child," the ant managed to squeak. "Been healing the weak. Pays not heeds to our credence."
Meliodas snorted. Oh yes. The religious laws humans made up around him and his clan, thinking they somehow bound demons. But, like the demons themselves, such creeds were riddled with lies, half-truths, and those lovely loopholes.
But just to be clear, and to prevent any inconvenient misunderstandings…
"She isn't a goddess," he said, straightening and putting one clawed foot upon the back of the bowed girl. She cried out from the weight on her broken wings. "But she's got a piece of them. Other than that she is mostly human, although," he moved his foot to lift up her chin with his toes, getting another glimpse of those eyes. As he did so, he allowed himself to admit that, without the dirt and bruises, the face he saw could be quite fine. "She's unusual and interesting. What is it you are asking?"
The rows of bowed humans behind the priests shivered, almost as one. Meliodas raised an eyebrow at this.
"We-we do not seek the usual peace or fruitful season," simpered the priest—who looked even uglier compared to this mutant damsel. "We, all of our people, wish—wish to have power, a specific power. That only the demon race could give."
His other eyebrow rose up as well. This didn't happen too often. Humans thinking beyond their next meal? Maybe his brothers had gotten soft on this world in his absence.
"Which is?"
"Power, sire, over the winds and clouds. We wish to summon rain upon our allies and destructive typhoons upon our foes."
Meliodas threw back his head with the force of his laugh, which crackled the air and made several humans faint. The fires shrunk and died.
"That is the power of a god!" he cried. "Are you gods? And you thought giving us a god would allow you this privilege? Fools."
The priest, who had been taking on the press of Meliodas's dark aura and then his chilling laughter without bending, finally collapsed onto his face.
"Please forgive our audacity—"
"Audacity is the least of it." He looked back down at the girl in the grasp of his long, clawed toes. She met his eye without flinching, though the spirit he saw in that gaze communicated as much emotion as a sunspot on the water. Even the tears sprinkling her lashes denied anything.
"This woman healed your kind," he said slowly, just to hear it out loud—so delicious. "Served you, even, selflessly, and you beat her and offer her life up for a little bit of power?"
How usual of a species who killed their own creator.
The priests head sucked even more beneath his shoulders. "For the greater good, and if this power is but little—"
"Oh, shut up." He dropped his foot, leaving the girl to slump back down to the ground. "I will grant a kind of the power you seek to a worthy bloodline in your village. It will not be all that you ask, nor will it be something you can ignore. Blessing, curse, it will be your consequence to bear for your own wickedness. Let it remind you to never reach for the heavens again, especially not through us. We may be the gods of this world, but we are jealous gods. You're lucky I didn't kill you for even asking such a ridiculous gift."
The priest quivered. "Yes. You are most giving, lord. We are unworthy, we will accept your gift graciously, consequences and all."
"Of course you will," and with that, he reached down to scoop up the broken young woman by her middle. She was lighter than he expected and didn't fight his touch. Only then did he spread out his curling, shadow-fire wings and reach out his hand towards the lowly creatures.
Though not a simple spell, it was far from complicated. He picked a bowed human at random to focus the words and power. Until he decided or upon his destruction, any soul with that bloodline would find a kinship with the wind that would allow them to summon it, fall in love with it, taste the freedom of it, but never, ever be able to be lifted up by it. No. They'd be tormented by the sky, all the while knowing more clearly than any other human that they were of the dust, and just as powerful as the dust, never to fly.
Satisfied, he gave his spell one last look over before lifting off into the air and vanishing from their sight.
His father would be pleased.