Alright, so Laufeydottir was going to have 10 chapters (plus the prologue and epilogue, so technically 12) and a sequel, Forn Fadir. I write in a very scatter-brained fashion, so throughout this you'll see bits of scenes and quips and the like.

Ch 6 began right away with Thor angsting about fighting Rel:

"I can't believe he pit me against you!" Thor stormed.

"Don't worry, little brother, I'll go easy on you."

Their battle features a lot of prowess from Rel (I had the idea that they'd be fighting two v two or the arena would be split into two battles: Rel is nice, but not as crowd-pleasing as the Hulk), but regardless of whether she would have beat Thor or not, she ends up throwing the match:

Thor dragged his gaze across the crowd before zeroing back in on the frost giant. He gestured to his helmet with a small grin. "See? Now I'm as tall as you."

Rel returned his grin as she crouched down, holding her sword out from her body. "Barely, little brother, barely."

*Later*

A dull blue suddenly burst from Rel's wrists and wove their way up her arms, and down her torso and legs. The color was followed by grooves and lines of markings stretching across her skin, cut through by long scars on every limb. In no time, the color had reached her face, and it ended at her eyes, which suddenly burst into a deep blood color, honestly not far off from the reddish brown of her eyes already. Her burn scar curved up the side of her cheek, nearly reaching her left eye. Her figure seemed thinner, lengthier, and aspects of her facial features had changed. Her nose was sharper, her eyes a different shape, her hair in heavier braids. Still, even though she had seemingly stolen her glamour from some unknowing citizen of the Nine Realms, she looked very similar to her less frosty form. Rel gave a frustrated sigh, and shook her wrists a few times. A slight pinkish pale began to seem into her skin again, but it was quickly overwhelmed by the blue. "Gah, I can't focus on bringing you back right now!"

The crowd was beginning to boo as Thor paused for a moment. He raised his eyebrow as she yelled at her wrist and a smirk suddenly popped across his features. "Don't worry Rellie, it suits you! Honestly, I was beginning to think you weren't even a frost giant. Just part of some elaborate ruse my brother pulled so that he could goad me about it for years to come."

She narrowed her eyes at him, and then leapt in his direction, lashing out with her blades once again. Her action was not very surprising and Thor dodged her gracefully, though she was close enough where he felt the frost off her skin. Grinning, Rel whirled around, holding her blades behind her back as she circled him. "You saw me freeze Hela, little brother, that's no elaborate magic. I'll freeze you too."

"You tried to freeze Hela. And because I am going to beat her, you will have no chance freezing me either," Thor grinned back feistily, and slashed forward first.

Rel throws the fight expertly enough where the audience believes it, and afterwards, Rel and Thor talk again while in the gladiatorial housing (or whatever it's called), and she tells him to prepare for a match against the Champion. When it does come, Rel is up in the Grandmaster's booth (the Grandmaster a little bothered she threw the match: "You threw the fight." / Rel shrugged as she perched at the top of the couch. "I didn't want to aggravate him. You should have just let him fight your champion in the first place. I promise it will be a more interesting show."). She banters with her brother, teases him a little (she sits right in the middle of their absurdly long couch, and is like: "You two are an embarrassingly far distance away from each other… What were you up to?"). We see Thor and Hulk's fight from way up here, and we see the end too- goes pretty much the same as the movie. Rel kinda suggests things to the Grandmaster, and because she's kinda low stress and a great fighter, he just lets her do things… she hasn't, like, told Loki who the champion is because she doesn't think he'd care. She's buddies with both Scrapper 142 (why she got Valkyrie to be paid in full) and the Hulk.

Ch 7 was the first of the two pre-final, somewhat shorter chapters: After the fight, Rel shows up with Valkyrie, and she also follows Thor when he escapes, with Hulk (who she's kinda already friendly with, like Valkyrie is). Banner is confused at who the hell she is, and freaked out upon learning that she's Loki's sister, but she guides them through the city, and almost has a tussle with Valkyrie when the scrapper finds them (proving her lack of loyalty- "where's Loki?" is her one phrase). Then, they gather together and make their plan.

Ch 8: So, as just mentioned, Rel's main and only loyalty is to Loki. Of course, she's fine separating from him, she's a grown woman, and thus she has no clue that he's being left behind when he does get left:

Thor gave him a tired look. "Your tricks don't fool me anymore, Loki. You've gotten obvious. Repetitive."

Loki's expression flickered, but he remained casual and shrugged. "Well, you are an idiot. I was beginning to rely on your stupidity."

Thor sighed and held up the remote that controlled the shocker in his hand. He gave Loki a pointed look. His brother canted his head in small surprise. "I guess you've come to rely on tricks too, brother."

The two had a small staring contest. The slightest tint of pain and pride, confusion and resignation hovered on the edges of Loki's expression. The god of mischief saw his best chance and reached to quickly remove the shocker from his back. The god of thunder clicked the switch before he managed anything. Loki fell over and convulsed. Thor approached him with a slightly sad expression.

"I wish you would grow, brother. I wish you would be my brother. But you resist change. And I can't trust you anymore. So here's where we part ways. Don't worry, I'll keep Rellie safe."

Loki was in obvious pain. The emotion flashing through his eyes was too open and far too sickening for Thor to stomach. Thor thought of how the shock had felt stinging through his chest and winced inwardly. It was probably worse for Loki. He didn't have lighting in his veins. Before Thor made a decision he regretted, he set the remote to the shocker slightly out of reach, hoping his brother would eventually be able to grab it, and turned away. He didn't look back at his brother. He couldn't.

"Goodbye Loki, and good luck."

Rel mainly spends the scene fighting off flighters with Valkyrie and Thor, but she very quickly realizes Loki is not around, and then she goes a bit ballistic:

Thor cut himself off.

The frost giant was laughing.

"Rel-" he warned.

"I'm going to kill you." A sword shimmered to life in her grip.

"Rel, he's alright-"

"He's certainly better off than you'll be!" Her cheery grin was nauseating, and her skin was starting to break out in random patches of blue as her glamour flaked off slowly. Her two forms dissociated as her thinner and gaunter figure was revealed underneath.

"You really are an idiot." Ice shimmered along her blade and a crystal dagger crackled to life in her grip. The last bits of her glamour fell away. Her grin was savage now, her eyes looked brighter red than normal. Snowflakes swirled in her hair.

"Rel-"

She lunged. Shot towards his left side and then in a last minute faint as he went to parry her blow, she twirled right and jammed her sword into his side. He caught it at the last moment, gasping in irritation as the blade pricked into his skin. He could feel the frostbite radiating off of her. She swiped at him with her free hand as a distraction, and then dodged backwards before he could yank either of her weapons from her grip.

Thor manages to knock her into the water, and then the rest of the crew leaves the planet.

Ch 9 was the first of the two final chapters that I planned to be pretty long. This chapter was kinda weaving scenes together from different points of view since our three main characters were completely separated from each other for the first time in the run of the fic; Laufeydottir kinda features Thor's perspective and Rel's a little bit too (Forn Fadir was gonna have Loki and Rel's perspective at the forefront), so I wasn't sure if I was going to weave in scenes of Loki deciding to go to Asgard (shows more deliberation and character development, partly based on past things, my idea was that Loki getting tricked by Thor was a jumpstart for him, something that made him finally come to terms with what kind of person he wanted to be), but between scenes of Thor/Valkyrie/Hulk fighting with Hela and her forces on Asgard, there are bits of Rel getting up out of the water, and snowflakes swirling around her as she begins to communicate with them, telling them that she doesn't have Loki. There's a voice that comes whispering through the air that alerts her to the fact that Loki has managed off Sakar and is heading to Asgard to aid his brother. She stalks off and the snowflakes swirl around her into a mini-blizzard, and then she's gone.

Ch 10: Back on Asgard, Loki has returned with a ship, and him and Thor don't quite have a plan yet (I wasn't sure how long I wanted to lengthen out the stand against Hela, given her intelligence, given my own interest in Thor searching for his friends; Sif, the Warriors 3, trying to get more people off the planet, making it feel like more of a ~war~). Then, Rel enters the scene (with the ice casket? I was still muddling through that idea) and reminds Thor of his vision, making him divulge the idea to start Ragnarok:

Thor spotted Loki. He was holding his helmet and looking about wildly, caught up in the fever of battle. He caught eyes with Thor as well, as the god of thunder strode towards him, and grinned. "You're missing an eye."

Thor grumbled back before facing the rest of the battle field. "You're late. We need to stop her, and I have an idea, but I'm pretty sure she'd get in our way."

Loki threw up his hands. "Hit her with a lightning blast then!"

"I just did and it did nothing! She draws power from Asgard." Thor flung his hand out towards where Hela was menacingly approaching them. Valkyrie and the Hulk were now on either side of the brothers. Loki glanced around and then his eyes widened as he was suddenly distracted by something else.

"Where's Rel?"

Thor sighed. "She tried to kill me. I left her on Sakaar. We can go back for her later. Right now we need to distract Hela. I have a plan, but one of us needs to get away."

Loki's eyebrows were heavy over his face, but he nodded, and turned back to Hela. Then, suddenly, before the dark queen could get anywhere near the four of them, a buzzing sound was heard from far off, and a small boat came flying quickly over the bridge, from the city. Hela didn't notice it at first, but with the attention of all four of her adversaries caught on a distant object, she sighed, turned, and rolled her eyes. "What now?"

Before anything else could happen, the figure on the speeding aircraft came into focus, and with the realization of who it was, came a huge ice blast that Hela was unprepared for. It fully engulfed the dark queen, who was now frozen to the side of the bridge.

Her eyes a blood red, and her skin as icy cold as her expression, Rel jumped down from the small flying boat, landing between Hela's frozen body and the pack of Asgardian defenders. She gave Thor and Valkyrie each a passive-aggressive smile. "Hello, little brother. Seems you underestimated Loki once again. And darling! Nice to see you too. Pushing me to my death was a very rude way to start our second date."

The two were astounded and wary, but Rel did nothing except smile. "Well! How can I help? Seem's you'd need a giant flaming monster to take her down for good."

Loki's eyes widened. "Sutur." He turned to Thor, incredulous. "You want to cause Ragnarok?"

Thor nodded. "It's the only way we can stop her. If we do manage to get away, she'll just wreak havoc on the universe in some other way. We have to stop her here and now."

Instead of Loki, Rel goes to the vault (Loki vouches for her knowing her way around, Thor is still hesitant, but she quips that she'll always come back to her brother's side), very obviously takes the Tesseract, and then they enact Ragnarok and get the heck out of there.

Epilogue… Touching final moments between brothers:

"You care. You really do."

Thor's smile was large and undiminished by Loki's rolled eyes and refusal of response. "I'm not all bad. I'd… like to change."

"Not words I'd ever expect to hear from you."

"Oh, you won't hear them again. This is your one moment, brother. I'll deny it ever happened."

And some set up for Forn Fadir. Speaking of…

Forn Fadir was going to be the next installment in this, and it was going to cover the span of Infinity War, with Loki surviving and the whole crew dealing with Thanos much more quickly and efficiently given that there was going to be a "bigger threat" on the horizon… Ymir. Ymir, the first of the frost giants, who Rel was communicating with through the snowflakes, and who had been awoken either by the attack on Jotunheim, or Rel stumbling into his sleeping place (he sees her and Loki's heritage as not something to be shunned, but treasured given that in my headcanon, frost giants are already adept at magic and Loki and Rel are both naturally gifted)… Rel was tasked with bringing her brother back home, so that Ymir could enact his plan, or whatever (plan involves getting other threats out of the way and enacting Ragnarok, similar to Thanos waiting to enact his plan until Asgard was destroyed). Title comes from the fact that she calls him Forn Fadir, ancient father (Ymir calls her Byleista, Death-Defier, based on Loki's actual mythological siblings… and probably Rel's real name).

The scheme of the beginning of this story was as follows: Thanos comes, Loki and Rel are allowed to stand off to the side as Thor is tortured, Loki actually doesn't have the tesseract and he pleads against Thanos, and Thanos is like, "ok, I think we should do your sister next" and Rel is like "that's actually a bad idea", she shows the tesseract, Thanos goes for it, Loki intervenes slightly and then the Hulk comes barreling through. Movie things happen with Heimdall teleporting people places, Thanos is angry, Rel tries to keep away the tesseract from him, but has to use her amulet or whatever she got from Ymir (which has been providing her with the snowflake connection, it basically houses a bit of ice and snow that Ymir can communicate through and use powers with which includes a limited teleport: one use got her from Sakaar to Asgard, second back to his realm from the ship, now there's one left, it can take her anywhere that ice is), and Thanos freaks a little bit because Ymir is supposed to be asleep (all the big baddies were supposed to be out of the way but he didn't count on Ymir waking up). Then he hunts down the other infinity stones now, just like before, but more cautiously. As movie plot plays out, Loki and Rel are off with Ymir and Loki's annoyed cuz he wants to help his brother:

"You lied!"

"I did not. You know lying, brother, that is not what I did. I merely withheld part of my story."

Loki snarled in indignation, and Rel returned his snarl with a cruel grin.

"I went looking for you, but it was impossible. Your existence really sounded like a pretty little fairytale that Hyrrokin had told me to keep me comfortable as I died peacefully in the wilderness alone." She tugged the royal blue cloak tighter around her shoulders as she gripped her chest. "And then I found our grandfather. And he told me that it was true, that I had a brother. That the two of us were not to be shunned, but treasured. That we had the capacity for richer magic than any frost giant before us, but that our father had cared more for our looks than our skills. We would become his disciples, true frost giants to rule over the galaxy in a new Asgard. Ymir had awoken because he knew Ragnarok was coming, he knew the time of the frost giants was upon us. He would not tell me where you were, but he directed me on the right path, and he kept me company as I went to find you. He showed me the way when I was lost, when you left me."

Eventually he convinces/forces Rel to come with him, and that angers Ymir but… eh, one at a time. So they show up on Thanos' planet:

Rel's eyes went wide and she gasped in delight, quickly ducking her way under Tony's arm. Tony sputtered as she strode towards the doctor. "Stephen Strange! By Forn Fadir's beard, it is amazing to see you again!"

Before she could get close enough to throw her arms around him, he held his hand out, frowning. "I thought I'd never have the… pleasure of it."

"Well, you have my brother to thank for that! He wanted to come 'join the good guys' instead of playing it safe."

Stephen looked past her to where Loki was still lingering behind Tony's outstretched arm. He gave a sarcastic thank you which Loki returned with an equally snarky curtsy. Then the god of mischief turned to Tony with a glare. "Have I been properly vetted yet?"

Tony lowered his arm and glowered back. "Yeah, sure, but I'm watching you, Frost Fingers."

Loki rolled his eyes and approached his sister. "What did I ever do to you?"

"Dude, you destroyed half of New York."

Loki threw a curious glance at the teenage webslinger, but before he could say anything, Rel jumped between them, put her head between her hands and leaned far too close to Peter's face. "What's your name, how old are you?"

"Um… Peter, sixteen."

"Sixteen… sixteen hundred? No," she muttered to herself and then turned to Stephen Strange again. "How old are you?"

Throwing his head back in agitation, he turned to her. "He's too young for you to hunt a boar for, if that's what you're after."

Peter's face grew more confused as Rel's lit up. She bounced after the doctor. "You remembered! Does that mean you accept? Will you teach me your magic?"

"No!"

And I think this time Thor heads to Titan… this plot was very scrappy, I wasn't sure whether I wanted Thor to end up sent to Earth with the Hulk and then on the ship with Tony and Peter, before he goes off to get his Thanos-killing weapon and they actually defeat him on Titan, or if I was gonna stick closer to the movie plot and they defeat him on Earth. But yeah, Thanos gets knocked down early (effectively halfway through Forn Fadir if this was gonna be another "10 chapter" fic) so everyone can fight Ymir. And… I didn't have the greatest idea yet of how that was going to go, but you can imagine that they manage it (with less fatalities than the og Marvel universe cuz I was low-key protesting that as well XD).

The rest of the notes I have on this are just characterization. Basically, throughout the span of Laufeydottir, Rel has been trying to help Thor because she's kinda trying to get him to go away so that she can wreak havoc with Loki alone, though she's kinda passive in her plan until Ragnarok actually occurs. So she's just sticking with Loki, passively helping Thor out, and kinda going with the flow, as long as she's still close to her brother. But when she's not… chaos.

Rel doesn't actually wants to hurt anyone (like, I mean, she's 100% focused on protecting Loki and will hurt people if they put him in danger, but that's because it's her mission and beyond that she's pretty neutral on everyone, and tho she doesn't admit it for a while, doesn't realize it at first, she does warm up to the others… she's still got a bit of those layers tho, that "can't care about anyone" even tho she does care, deep enough down). And she does somewhat enjoy being part of the hero team (she might even compare and measure with Loki; "It's nice being a good guy, isn't it?"-R "You can't imagine."-L… who then probably goes into a "but you took that all away from me", with the added dose of "I still can't seem to say no to you"), and she doesn't ever mean to hurt them while she's there, unless her brother is in danger, because she though she lost him once, and now that she has him, well, he's her family, she can't bear to lose that (she might admit missing Thor when it's just her and Loki too), and he's also her purpose and mission.

One last thing Rel's emitted from her story to Thor: Her jealousy for Loki. She thought he was weak when she first heard his life's tale. He had a loving family. Some of that love was built upon lies, but most of the lies were things he told himself. Lies that no one cared about him. But Loki understood her tale, and she understood him back. He always had an uneasiness about him, it was in his nature. And they just clicked. He was immediately protective of her. He didn't trust her, but he couldn't ever say no to her. He watches out for her because they have similar natures. They both know pain. He doesn't trust anyone. He can't relax, can't accept things to be true. He watches out only for himself- and for Rel. She's like a part of himself that he's protecting. Agony he never experienced, never knew, but agony that's somehow so familiar to him. And she needs him, she needs family. That's why she's so dedicated to his safety and to joining with Ymir… Loki probably mentions Thor: Thor can be our family. He's realized that. Part of his character arc in this story is cementing that (anti-Ymir talk: "this isn't actually family love, you just accept us because we help you"). He has Rel there, and Rel is kinda encouraging him to stray away from Thor and just live as a little family unit, but he recognizes himself in her, realizes what she was doing. This stuff is revealed in the second installment, this change that Loki's gone through, he tells it to her. Explains it. Thor was getting done with Loki just as Loki was fighting his way out of his hateful, fearful state, something he finally recognized by hanging with Rel. Rel would bring up Thor tricking&abandoning Loki (He left you! He hurt you!)… see, a lot of Loki's growth has come from meeting Rel and finding someone who he feels a deep familial connection with, and it's made him more self-reflective (including of his relationship with Thor). Unfortunately, Rel hasn't quite grown from her interactions with Loki (and Thor). She's still bitter and angry and untrustworthy with a good old mask on top of it all. She thinks Loki should be scarred by Thor abandoning him, despite him not being so.

Also, at first it seems that Rel goes back to the good guy side rather quickly, but she is deep-down a bit resistant, and a bit worried… Ymir isn't fully pissed at her yet when she leaves to fight Thanos either, but that's what she's worried about, that happening (and then it does and there's probably some struggles on her side but eventually Loki convinces her of what he's learned it really is to be a family… and powerful ice magic that dwells within Rel&Loki is key to taking the ancient frost giant down/putting him back in slumber/idk).

And I'll leave you with this (me being silly):

Thor: Ah, a snake! I love snakes!

/He reaches down, then glances to the side/

Thor: I know it's not you, brother.

Loki: *shrugs*

/He picks up the snake/

Thor: Aw, aren't you a cute one-

*STAB*

Rel: *giggles, knife in hand, no longer in snake form*

Thor: REL!