Unneeded
Loki Laufeyson is the most precious weapon in Asgard's arsenal.
Found in a ruined temple by Odin, brought to Asgard as a means for treaty. The plan turning out inadequate when it was revealed that Laufey the Jotnar king got rid of the child himself, ashamed of having fathered a runt.
It does not matter. The Allfather's mind is all-seeing and omniscient and he soon finds another use for the foundling. For Loki bears a magical power unknown across the Nine Realms, even amongst his own people; one so strong his mind cannot handle it, descends into madness.
That is of no account. It's not the Jotunn's wits Odin needs.
Loki's reputation is well known among all the worlds and kingdoms existing. His name itself holds enough threat to chill the mightiest warriors to the bone. When on battlefield, his fame and strength is carried by the buzz of magic and thrum of the soil beneath, enemies running for their life long before Loki himself appears.
His might and thirst for blood is only known from gossip for no one who gets close enough to experience it themselves lives to tell.
On his coming of age Thor receives Mjolnir and command of a division of warriors to lead. The Allfather takes him into the dungeons and beyond, into a section of the palace's undergrounds Thor's never been to before. There's excitement buzzing under his skin because he knows this is where Father keeps his mightiest weapons; the biggest threats to the worlds he possesses.
The heavy doors enchanted with runes are being guarded by Einherjar who straighten their backs and salute as they pass by. Inside there's a cell, more runes etched into the stone across the floor and the ceiling, buzzing with power, moving at the edges of their vision.
Thor holds his breath. There, behind a slightly wavering barrier of magic.
He looks inconspicuous. A true runt, not only in comparison to Ice Giants but Aesir as well. Clothes torn into rags, barely concealing his privates. Shackles around his wrists are connected to a heavy metal collar, keeping his clasped hands at chest's height; both engraved with even more meticulous runes. His feet are also manacled with a short chain between them, another one connecting them to the handcuffs; the chains are tight, preventing any movement of arms. Another chain, protruding from the collar, disappears into a wall behind. It's maybe three feet long and Thor notices at the back of his mind that the prisoner couldn't possibly lie down, the chain already pulled taut as he kneels with his head slightly bowed.
There's a muzzle over his mouth, covering almost half of his gaunt face. The other half is hidden behind black, tangled hair, a disheveled mess reaching his elbows. From behind that, a pair of sickeningly bright eyes is boring into them, the light of a single torch flickering in the wide blown pupils.
And he doesn't look like a Jotunn. His skin is the palest white Thor's ever seen.
He can't help a shudder that runs from his head to toes.
Asgard's mightiest weapon, Loki the Destroyer. One Odin hasn't used since the great war with Jotnar when his son was just a baby, for no one dared to rise a hand against the kingdom since then.
He dares not take another step, watches Father near the cell, hands behind his back, looking at the bound man in contemplation.
'Our people say I am omniscient,' his loud voice booms off the stone walls. 'That is, unfortunately, far from truth.'
Loki's wild eyes follow Odin who walks slowly along the cell. He doesn't move, doesn't make a sound. His shockingly thin body is tense, every muscle pulled taut.
'For instance, I am hesitating what to do with this beast.'
Thor watches with wide eyes, jumping from Father's profile to the unobtrusive being kneeling on the stone floor.
'It wields magical power greater than any other creature in the Nine Realms.'
Even you? Thor wants to ask, but his throat is too tight.
'Norns bless us, I have not had need to use that power in centuries.' Odin turns to the cell and Thor's breath hitches when Father reaches out a hand, the magical barrier giving way to him like water. 'But I am not ignorant nor optimistic enough to believe I will not need that power in the future.'
He circles the mage and stops right behind him. Loki's head twists, trying to keep his eyes on the god, but suddenly the Allfather's fingers bury in his wild tangled hair and twist. A barely noticeable hand movement and the muzzle disappears, revealing pale skin and sunken cheeks. Hair falls out of his face when Odin pulls his head back.
Loki makes a growling, animalistic sound, more of a beast than a thinking being. He snaps at the air, revealing sharp teeth, hisses and barks and his whole body twists, fighting the unrelenting grip. A wild animal, really. Not much more.
'That you will not need it.'
Thor first sees him in action a century later when the Dark Elves try to invade Asgard in a show of greed and lack of sense.
It's thrilling. He's never seen power so raw, so deadly in its primitiveness. The moment his shackles are removed Loki explodes with magic. He's never been taught to wield it; that had not been the point.
Seidr is a living force merely inhabiting the wielder's body, he's been told. It needs to be released regularly or it builds up, does damage to body and mind both, feeds off them until there's nothing left but madness. Loki's magic had been bound for centuries.
He causes destruction wherever his eyes land upon, bodies of the enemy ripping apart or twisting in the most painful ways imaginable. Air crackles with magic and flashes with green and where there's no green there's red, for he tears with his bare teeth at the throats of the ones unfortunate enough to live through the first wave of his wrath.
Thor gets lost in his own bloodlust, swinging and smashing until there's no enemy left to defeat. His armor is splashed with gore, Mjolnir thrums with excitement in his palm. He's found himself in a forest at the final stage of the battle. There's only bodies and wounded around him and he sees none of his warriors, but can hear them yelling and then that unmistakable, primal howl.
He swings Mjolnir and lifts himself above the trees.
The trick is to bond Loki before he turns against the Aesir soldiers in his mindless bloodthirst. Thor notices him easily, a plain of open space among the forest, trees broken by outbursts of magic, torn bodies piling up.
A thin figure standing in the middle of the massacre, Aesir warriors circling him loosely, keeping their distance.
His skin is blue and wild eyes scarlet red.
Thor does not hesitate and slams full force into the mage, the impact throwing them good ten meters before they stop, the Prince on top. Loki snarls and blasts a globe of hissing light at him, and he avoids it by a hair's length. Clenching his teeth he fists his hand and delivers a blow to the temple so hard Loki's head snaps and his eyes fog and Thor uses that moment to turn him around, slam his face into the blood soaked soil, grab the clawing hands behind his back, digging his knees in the trashing figure's shoulder blades.
'Give me the cuffs!' He yells. Loki trashes under him like a wild horse, tries to throw him off, twists his face in the mud to snap at Thor's flesh with his blood stained teeth but in this position he can't attack physically nor use his magic. Someone approaches with the enchanted cuffs and he fastens the shackles quickly around Loki's thin wrists.
The Jotunn's body stiffens and he moans painfully, the most human sound he's made yet. Then he goes limp, forehead pressed into the soil, fingers twitching at his back.
Thor stands up slowly and throws the hair off his face. He nods and a group of soldiers is at Loki in a moment, pushing him brutally to his feet and starting to drag him towards the camp.
His face is twisted in what must be excruciating pain and he does not struggle, dizzy and half-conscious. Skin changed back to its Asgardian disguise, greenish eyes hazy.
'No...' He moans weakly, and it's the first time Thor hears the beast speak. Didn't think him capable of it. 'No...'
Having all that boiling magic bound in his body again must be a torment beyond anything.
Thor begins towards the camp himself and realizes he's never been so hard in his life. He returns to his tent and pleasures himself with his hands still covered in blood, closes his eyes and recalls that wild trashing body beneath himself, how it fought him beautifully and how it felt to tame it.
From his youngest years, from the moment the thrice cursed Allfather finds him in the temple, all Loki knows is pain and the cell.
Every day of his growing they starve him, humiliate him, whip and kick and beat his body until he's a mess quivering on the cold stones in a pool of his own blood.
Odin Allfather chooses his men wisely. They're the best of the best in their trade, and they train the Jotunn to be no more than a savage broken beast, a scarred animal that lashes back at anything that approaches because it only knows pain.
They teach him that. Carve it into his skin and his mind. Make sure that for the whole of his miserable life, he only knows spite and fear and the agony of tamed magic tearing from the inside at his very being.
Sometimes he manages to fall asleep and he dreams. Of blue skies and gentle hands and a voice singing a lullaby to him. When he wakes, he can almost feel all of that at the back of his brain.
He doesn't know how the sky looks like. His moments outside are when magic takes over him and he remembers nothing of that, only the taste of blood on his tongue and electrifying buzz of magic on his fingertips.
He can barely form coherent thoughts. Feels more than thinks. Knows a handful of words, those he hears from the guards and the trainers. All associated with humiliation and pain.
And yet. The worst comes always after the battle, when they retire to Asgard and he's being dumped back into that cell that's his whole life. Has always been. Will always be. He knows nothing beyond that cell. They tie him up and leave him there, heading off to feast and celebrate another great victory of the mightiest realm.
He's not needed anymore. A weapon put in its place to wait until the next time the Allfather deems its use necessary.
He slumps against the wall as low as the chain at the back of his neck allows him. Lays limp and hurting and broken and silent tears fall down his face. He does not know that crushing feeling constricting his lungs and pushing water out of his eyes. Sadness is not an emotion the Aesir need of him and so he's never been taught to pin it.
It only comes in the moments of clarity, after a battle, when his magic calms a little, its accumulation lessened and power spent.
It's then that he hallucinates of gentle touch and red eyes and cold dampness falling from the sky. It's then that he hears soft murmured words he does not understand.
When they come back to whip him and burn him and smash his face against the stone he welcomes it, for the pain once again becomes all he knows and Loki longs for what he'd been robbed of no more.