At last, the first part of a genuine Finn-Thor story and getting this plot I'm been sitting on going! Thanks for inspiring me, Stinky Foot and Neverthrive!

Disclaimer: I don't own either Adventure Time, Scion, or Marvel comics; those belong to their respective owners and I make no profit off them. Norse mythology is public domain, though.

Sometimes, in the darkest corners of night, when his dreams were long and reached deeper into stranger corners of his mind than he knew were even there, Finn remembered from before Boom-Boom Mountain.

A hammer in his hand, screaming his name and bringing heaven down on the faces of evil. A face with a missing eye and a gruff smile that spoke to him with the voice of a father. A grinning maniac with scarred lips twisted into a brother's smile and flame-bright hair, eyes promising chaos and disorder and so dark with pained madness that Finn despaired of ever saving him from himself. A woman smiling at him the way he always wanted Bubblegum to look at him and her head crowned with hair of gold: not just the bright blonde of his own hair, but REAL gold, woven somehow out of the pure metal stuff. Two boys with the same bright red hair, big and strong and one wild and the other quiet; a girl that looked so very much like them but eager to bust some heads, and a taller man with the same bright red hair and a burning weapon in his hand and a honest smile that reminded him of himself so much it hurt. And other people, distant and strange and human.

Sometimes he suspected that these people were his family. It was a thought that came whispering up from the depths of his sleep, and it hurt nearly as much as it made him happy.

There were so many faces. So many voices, so many people he didn't know and he knew and had forgotten and he didn't know who they were or why they haunted his dreams and nightmares.

The nightmares came more frequently, like they were supposed to happen. Or maybe they were telling him things that were destined, and try as he might he couldn't remember them all, and some he couldn't forgot. A giant that was two miles tall, holding a flaming sword and made of fire, his eyes glowing with pitiless light and Finn knew he didn't want anything except to burn the world and kill every living thing on it because that was just the sort of thing he did; fire wanted to burn, and he WAS fire's mean side incarnate. An enormous wolf, so big that there were mountain ranges shorter than its knees, bearing down on the one-eyed father-man with its jaws spread wide and the sickening certainty that this man was going to die and he cussed well knew it, and was going to die fighting the Wolf anyway. The fire-haired man with the scarred lips fighting to the death with a massive man who glowed with the same justice-fueled resolve Finn recognized in himself, and the scarred man danced and screamed like a man watching his children going to their doom and laughed like a broken animal gone utter insane with its own misery, and when the other man drove a sword through his mouth and stilled his tongue, he seemed almost grateful.

It's the last one that really bothers him, makes him waking up shaking and whispering in a language that hasn't been spoken for over a thousand years: he sees himself, standing at the end of the world as the giants of fire burn the world and his family dies, one by one, in a fight they knew only a few of them would survives, and their deaths are horrible, terrible enough to make him cry at their awful doom even when he doesn't know their names and all the worse because the knows that they knew they would die being pulled in half and with swords through their heads and burned alive, and then it's his turn. Just himself, and the ocean pulling up from the world and ripping up into the true shape of a gigantic serpent so large it encircles the whole world in its coils, a sanity-defying behemoth that's just too big to exist, and then it's just him to fight it. He is the only one that can slay this monster, because he's the Friend of Humanity, the Lord of Storms, the thunder given a voice and a name, and the people love him and that love gives him the strength to die here and now.

And he doesn't remember what his name is. For some reason, that rankles more than watching himself die cracking it's continent-sized skull open and spraying himself in its god-killing poisonous blood, and then it's just crashing to the ground, and then he takes nine steps, striding like a giant.

The hammer - his hammer, powered with all the force of his mountain-uprooting strength and the force of his legend - falls from his hand. The red-haired boys and girl who look so much like him watch him die standing, eyes brimming with tears and horror owed from children to a father they have watched die.

Finn always woke up then, feeling like something should have happened but it didn't and it's probably a good thing but now the world's all messed up and it's his fault.

And outside, the storm crashes and rages, echoing the confusion he feels.

Here and now, someone that had come to be called Finn the Human but had once been called something else dreamed anew.

There is always thunder, and fire, and birthed in human-like shapes, they had warred for eons.

For so many years, they have been pitted against each other; too many years of bitterness had driven the trickster mad, and against the world that the lord of thunder loved so much. Ages of battle, ages of combat, of heroes and villains warring for forever.

But now, the heroes were dead or turned away from the world. The villains had passed away just as surely. And now, at the precipice of all things, the lights came down, stars heralds the death of the world.

The god of thunder stood beside the god of fire and chaos; for too long, they had been enemies. Perhaps they had been brothers once, or just brothers in arms; that had been forgotten in the hatred and the violence. Now, for the first in a long time, they felt like family again.

The god of thunder took in a deep breath, and the storm seemed to breath with him. Hair that was either red or blonde stained with so much blood as to be red hung lankly at his side, as the two of them stood upon a small hill of the dead. His eyes seemed empty, drained of the life that had once burned in him like an eternal lightning storm. Beside him, the god of fire said nothing as the god of thunder wept silent tears. Finally, in a voice of roaring booms, the thunder-god said, "We could have stopped them. We could have saved them."

"Why bother?" The other says, his voice whispering like oil, promising lies sweeter than honey because the truth was a poisonous thing that hurt so much. The world had burned him so, had seen his children cast away. He was the father of monsters, and no father was so mad to see his children avenged as he. "They… they cast us off. Surplus to requirements. We should have let them die."

His voice was hollow as he said this. Even as he spoke, there was no belief in what he said.

The thunder-god, taller and broader, turned his eyes to his friend. The fire-god flinched for a moment, and then his eyes drifted to what was on the thunder-god's wrist. Like a bracelet, shining beautifully; hairs made of solid gold, wrapped around his wrist like a blanket, and the roots of them were still bloody.

For a moment, the thunder-god knew that the trickster thought to say the name of the thunder-god's dead wife, now lost the wars in heaven that matched the war of this world. The smaller one (and how odd it was that he was small at all, he had been born a giant of Muspelheim after all) worked his mouth uselessly, and stopped.

There was a madness in the thunder-god's eyes now. Grief and rage mingling into a berserker fury that could burn the world and scorch it to ashes long before Ragnarok ever did.

"They're going to die," the trickster said, suddenly. "The humans will die." He gave a long look that for a moment, was sad.

The thunder god looked up into the sky. Even now the lights were coming, the stars heralding the doom of humanity. The World would die, burned in nuclear fire.

He licked his lips. "No," he said suddenly. "I say nay."

The trickster gave him a startled look. They were surrounded by a crater they had cracked into the world with the expressions of their raw elemental power, they were surrounded by the bodies of demons and devils and worse than that had rose into the world as magic became ever stronger, and there was a curiously amusing mundane quality to his expression now.

To his brother's questioning look, the thunder-god only looking up, with a strange sad smile twisted the red of his beard. "I'm sorry," he said after a moment. "For everything."

"What?"

The thunder-god didn't answer him right away. "Not enough time," he said. "Never enough time to fix everything. But I can stop the worst of it."

"I don't understand-" The trickster was one of the most intelligent beings in all the nine realms. The unceasing currents of his mind put it together for him. "No… please, don't say that you mean what I think you do."

A long pause, and then, as the wind picked up and the hammer in his hand glowed with power, the thunder-god said a final thing. "Goodbye."

"…No," The trickster said as the wind roared and the thunder-god began to lift up from the ground. "No. No! No, damn you, DON'T DO THIS-"

The wind blasted the thunder-god into the sky, and knocked the trickster down, keeping him from following. The thunder-god flew into the air, towards the lights of humanity's doom, and for a moment he looked down; the crater below receded, far into the distance, and he saw the armies waging against each other, the lights of artillery firing and guns blazing, thousands of men and women killing each other against the backdrop of what had once been his beloved Norway-

The people here had loved him, once. But that seemed a long time ago. Back when his friends had still been alive. The Captain of hopes and dreams. The man of iron and science, who had given to the world a bounty of knowledge that had made the world safe and happy for a time. The monster who was a man, and who was not dead but had left the world to rot after too many years of being hated and rejected just for what he was… and that had been before the mutants had been cast out, cursed to wander through space and never return to the planet of their birth.

The Age of Marvels had been a long time ago. The thunder-god still remembered, and he wept to think of how long ago things had been.

For a moment, as he ascended up and into the clouds, he looked back to his brother, his poor mad and prideful brother, who at long last had stood with him at the end of all things. For a moment he saw him staring up in horror, hair blazing like fire and the scars standing out like a crude smile on his face.

So sad, to see that face that had once been so bright and beloved by his people, to have gone so terribly astray. And now the trickster stared up, and in that moment his face was so empty, all hope and life gone-

The thunder-god averted his eyes. "I am sorry, brother," he whispered again, as burning hot warmth went down his cheek and fell to earth like tiny meteorites.

He left him behind, and as he flew through the clouds with such speed that super-sonic booms sundered them, he heard the trickster scream, a sobbing and maddened pleading to please come back.

The thunder-god looked as he saw the light coming to him. A shell of metal and blazing on a trail of fire; not a light, but a bomb, of mutagenic horror and nuclear flame both, and behind it came dozens of others. Whether they were from one nation or another didn't matter; they would all burn the world.

The thunder-god drew his arm back, tears still flowing even as he grinned like a madman. The bomb came to him, thunder crashed in the clouds around him like music for this final act. He thought, for a moment, of all his life before; of coming to Earth and becoming a god of the Norse people, of growing up with the trickster and watching him grow mad as the years went past until the fire was gone and there was only a despair expressed at hatred. Of coming to Earth again to pay for his arrogance and finding friends in heroes and allies.

Of watching those friends die. Of all their good work undone, and seeing the Age of Marvels they had wrought with sweat and blood come undone.

Of seeing the world go insane, and the madness overtake the world, and here to the inevitable conclusion.

For a moment, he thought of golden hair and a warrior-woman's smile, even in death as she died in his arms. Of his children dying just the same.

Perhaps it was madness and grief that compelled him to this moment. Perhaps it was heroism, and knowing that this was the only choice he could make on short notice.

Either way, he was still smiling and shouting as the lightning screamed from the clouds to his hammer, filling him with even greater strength as the bombs came.

"For Asgard!" he yelled. "For Midgard! LET THIS NOT BE THE END!"

He swung his hammer into the bomb, with a strength that could sunder mountains and unmake the titans who would threaten his beloved humanity.

The bomb erupted, and the last thing the god of thunder saw before the light of death overtook his legendarily mighty body was all the bombs exploding in a chain reaction, and the world burned-

But it was not as terrible as it could have been. The World would live. Humanity would survive.

So, the thunder-god smiled even as he burned. His suddenly nerveless fingers let go of his hammer, and the enchanted weapon of the thunders flew away, cast off by the force of the explosions, and the thunder-god's body was disintegrated into ash-

Finn jerked up, gasping and covered with sweat as the thunder boomed overhead, so familiar and so close that it hurt to feel the sky so close at hand.

He heard a voice, sweet and clear. "Whoa, little buddy, snap out of it!" A gray hand was shaking him, slender and scarred, and Finn blinked for a moment, his head tilting upwards and focusing on Marceline's eyes.

"Finn, are you okay?" asked Princess Bubblegum, sitting behind Marceline and holding a stick; she looked like she had been about to poke Finn in the eye with it. Next to both women sat Flame Princess, burning bright and looking spooked, her arms reached out beside Marceline as if she wanted to hug Finn but remembered herself at the last moment. Bubblegum poked her with the stick, saying "Shoo, shoo!" and Flame Princess gave her an indignant look, waving her hands at her ineffectually.

Finn shook his head. "I don't… what?" He looked around dazedly; he noticed eventually that he was sitting inside a cave on a thick sleeping bag. The three girls and him were crowded around part of the dome-shaped cave, and a little bit off was Jake and Lady Rainicorn, sound asleep and wrapped around each other, apparently unaware that Finn was having issues again.

A sleepover, he remembered, up in the mountains. They were hiking to some other kingdom for a fancy diplomatic thing, and Bubblegum wanted her friends to come with her because she got so bored at these things…

Finn shook his head, dislodging more of the blanket. "I… what was I doing?"

"You've been shaking around and muttering for like, uh…" Flame Princess thought about it. She grimaced; clear thinking and careful consideration was not one of her strong suits. "I dunno. A bit, I guess. A long bit?"

Marceline grinned at that. She opened her mouth. "Don't you make any dirty jokes about that," Bubblegum said dismissively. Marceline pouted, looking annoyed.

Finn puffed his cheeks out. He clutched his head and whimpered as the thunder boomed outside, again and again, like the barking of a pet that worried for its master. "Just a dream," he said. He tried to grin. "Just a dream, that's all!"

The girls didn't look convinced. "What was it about?" Bubblegum asked, curious, pushing Marceline aside and grinning like if she wasn't in front she wouldn't hear Finn's dream right.

"I dunno," Finn lied. "There was… um…"

He remembered the trickster, the god of fire, screaming like he'd been physically hurt when the thunder-god had flown away. And he remembered the coldness, the fear, and that horrible gray feeling of nothingness.

And the burning. The pain. The feeling of dying.

Finn swallowed, his hands feeling sweaty. "Do you girls know how the Great Mushroom War actually happened?"

"Why you asking something weird like that?" Marceline asked, raising an eyebrow.

"…Nothing. Dream." Finn shifted uncomfortably, feeling that maybe the word memory was more appropriate.

"I don't really think there's much I can say about that, Finn," Bubblegum said, shrugging and looking disappointed that she didn't actually know enough here. "I… suppose we have an account or two from survivors, but I don't know if they're actually for real or not. And there are a few long-lived people who actually survived it, but…" She gave Marceline a look for some reason. "Either they don't actually remember much from that time, or they're in no fit state to give accurate information."

"…Oh," Finn said, feeling inexplicably relieved.

"Go back to sleep, Finn," Flame Princess said. "You're being messed up in the head-a-jamma."

Marceline and Bubblegum looked at her. "What?" Bubblegum said, sounding amused."

The younger lady flushed. "…Something Finn says," she muttered.

Marceline raised an eyebrow. "You're a bad influence," she said wryly.

Finn smiled, and to the voice of his ladies talking like that, gently lay back down and shifted back into sleep. Above him, thunder raged and lightning struck.

For Finn, there was warmth and love waiting for him as he awoke from his dreams.

For another, there was only insanity and bitterness when awake.

In the mountains above the Grasslands that Finn called home, the Magic Man hid from the world, a green figure clad in filthy yellow rags huddled in a cave and nearly every inch of that cave had been carved with words he put there.

Crouching there, whispering nonsense words to himself and sweating like a wild pig; a long time ago, there had once been a god of trickery and genius. Who stood beside the one-eyed master of magic and power as his son, and beside the mightiest hero-god of all to call him brother.

But that world, that world of heroes and marvels, had turned away long ago, bathed in nuclear fire to make this brave new world. This madman known to all as the Magic Man was a poor remnant of that age of marvels.

His name wasn't really the Magic Man, but he called himself that anyway. And anyway, his true name had ceased to be spoken long ago. He had not spoken his true name in some time; names had power, and he knew quite well that the boy who he'd come across by pure chance mere years ago (when the boy had only been twelve, fancy that), he knew who he was, what he was.

A long time ago, before the world had burned and he had not lost all that he was and fallen into this wretched mimicry of what he was…why, he who had become the Magic Man had called the being who became Finn the human "Brother." But that was before the world had ended, and the gods of humanity had been forsaken.

He had once heard it said, 'all it takes to drive the sanest man alive to lunacy is one bad day'. In his case, he'd had one bad aeon. And quite a few bad days since then. The thing on Mars, with his lovely girlfriend-

-warm lips on him and a hand to be held, sitting together quietly just talking and knowing that he is loved and wanted even with the weight of his fate on his haunches like a feral beast, and then she is gone, dead and lost, and something in him has broken-

-was only the latest of tragedies. Sometimes, he missed Mars.

Not nearly as much as he missed Asgard.

Dust on dirt and dirt on stone, faded remnants of permanence on stronger permanence to support him and the World, and the Magic Man realized too late when he looked at the patterns his roving finger had left in that dust; it was a word, imbued with hatred. Hatred for names he'd pretended to not remember any more and had left this world since before the Great Mushroom War had driven the humans mad, hatred for the world for forgetting their gods and leaving them alone, and most of all for himself. Hatred undiluted and festering for more than a thousand years before the World had been remade in alien-brought war and nuclear fire.

He stared at the word he'd written on that dust, over and over. He twitched, first one way and then the other, blazing embers fading in and out around him with his every breath. The word 'TRAITOR' was written boldly a hundred and six times by coincidence and then admission, and stared at him, a confession and a cry for help.

His lips worked. And then, a voice that does not belong to the Magic Man but a being far older and terrible whispers, "I have only ever done what I have wanted."

And all he can think to that, is 'look where it's gotten me'.

It was an effort to stay still and not run, run away from all the terrible things laying behind him that were well and truly all his fault and no lies could wash away. He could warp reality and reshape the world with his lies, but he couldn't change the past. Not by the Odinforce, not with the Infinity Gauntlet, and not even if he had all the power of Muspelheim itself. The guilt and hate burned like he'd swallowed lit coals, and the echoes of himself knew that it was a travesty that he should feel guilt about anything at all and still other echoes screamed shame at him, screaming long and low in the dark until they were furious whimpers begging for absolution.

He let the voices scream and scream, arguing with one another and rising so high that they blurred together, a psychic storm upon his brain beating against the shores of sanity until past and present almost blurred into one, and then at last sanity prevailed and silenced them for the time being. The Magic Man almost wept then, half in self-pitying grief for himself and half in honest grief.

He puffed his cheeks out and blew out bitter air, heat rising from his eyes to burn away the shameful salty wetness. "Just leave me be," he muttered, holding his hands up over other names he had written into the ground; names no living being would recognize today. 'Baldur' and 'Hodur', 'Tyr' and 'Sif', 'Fenris' and 'Hel' and 'Jormagundr', a dozen other names and above them all was 'Odin' and most especially 'Thor', beating in his head and his heart like a wire touched with flame enough to melt through with all the hate-touched love his bitter heart could muster.

One hand laid against the ground, ready to wipe the names away, strike them from the sight of himself and the World and get back to the business of pretending not to know himself and all the cares he carried inside, resume the lie of being anything other than the reality-warping master of magic that everyone in Ooo regarded with a mixture of annoyance and dread.

His hand started to move, dragging dirt along the way, and stopped just short of the runes that spelled out the name of Thor.

He gritted his teeth, bunched his muscles, and dragged his hand a mote further.

The dirt spilled up, staining his hand, and at least he could bear it not more and pulled his hand away, clasping his face in his hands and weeping. "Damn you," He whispered, not really feeling the hot surge of hatred that his memories promised that he ought to feel. Just this sullen ache where all his real feelings ought to be.

By the Eddas, he felt so Fate-damned tired.

If any dared to spy on him then, they would have not seen the Magic Man at all, the lie-spun illusion of the false man flying away in that moment to reveal a broken and miserable sight, a man as green as the most bitterly envious monster still mourning the doom of its monstrous brood, clothed in yellow tatters and a cone-hat tottering dangerous as he rocked back and forth.

That image flickered and vanished for a moment, and so they would have seen something quite different; a thing that had not walked unfettered in the
World since the world-breaking bombs had fallen, and the thunder had been silenced. A thing of fire and chaos, the father of a thousand-score monstrous men and women, the architect of the end of the world-that-had-been. The father of the Wolf and the Serpent, son of monsters that had spilled the World into birth (depending on the cosmology), one of the greatest makers and villains of the bygone Age of Marvels.

The Trickster incarnate; the Void and the Devourer and the Wyrd. He whose casual musings held more genius and inspiration than the greatest brainstorms of all the mightiest minds to have ever lived, a liar so good he could reshape the world with a whim and break apart the minds of mortal men only to put them back together as he pleased. And for all of that, he was now little more than a damaged shell of the God of Flames and Chaos, held together at the seams by habit and ragged strips of bullheaded stubbornness, threatening to fall apart at any moment from cosmic inertia and madness.

A thousand years of grief and loathing, torn apart and built back up by hatred, and his thoughts circled and moved, like a sickening raven returning to the same rotten carcass, and time and time again his thoughts returned to the boy, the hero, and gradually his weeping ceased, and in its place was a silence far more foreboding.

"Finn," He whispered, tasting the name of the boy he had met a little over two years ago, feeling the rumble of distant thunder when his own power-fueled voice spoke it, feeling the traces of the true name forgotten and buried under layers of humanity and yet still very much the same. "Finn." He laughed. "So. That's what they call you now. The Tuatha would be jealous."

The skies had been clear only moments ago. Now they boiled with thunderclouds, thick and dark like chained dogs and savage goats longing for their master, and roared with the booming of ten thousand thunders, shaking the land and bending windows and calling people from all over Ooo to cower in their beds. From coast of swimming shark-people to past the Fire Kingdom with its fire elementals feeling a distant kinship to the lightning birthed in the skies above, and the mountains with their minotaurs and giants pausing to stop long enough to feel an ancestral shiver at the storm's coming, and still the storm screamed, wild and reckless and totally abandoned to this perfect rage. Even the Magic Man shuddered at the thunder, for he had never been overly fond of what came afterwards, and he fancied that he could feel old Hunson Abadeer flinching at the thunder even in his prison-kingdom.

Perhaps, the Magic Man conceded at this display of power, the World had not forgotten the names of his kin after all. He stood up, and the names and words in the wall burned from within as, burning nearly as brightly as the flames that were his true heart under the lie of form, and thought, not for the first time and certainly not for the last time, that the Magic Man was a lie that had was due to be abandoned.

He had kept it going for too long. Enough (and the words landed inside his heart like little worlds blooming to life in blazing cataclysms that were so deeply engraved in his fate) was enough.

That thought in mind and more flowing from the unplugged well inside, the Magic Man mumbled to himself for a good long time as he started walking.