So...my last few chapters here got some interesting feedback. My first attempt at a Sword Art Online fic was divisive. Look, I know Sword Art Online itself is divisive, but on the poll currently on my profile (as of writing this), it's near the top of the results. An SAO crossover is still on the cards, even if it won't be done exactly like I did Stranger in Strange Lands. Maybe that will see the light of day as a full story, maybe it won't.

As for the Harry/Raynare fic, Azrael Rising won't make an appearance. Don't get me wrong, I still want to do a Harry/Raynare fic, and that's still on the cards, but I'm having some trouble deciding how to do it. However, I had a bit of inspiration for another High School DxD-related pairing that I've wanted to do for a little while, for a character who doesn't seem to get that many pairings, beyond being part of Issei's harem, and whose character is ripe for expansion. Oh, and her name also starts with an 'R'.

Yep, it's Rossweisse.

Now, for the sake of this story, she (and Harry) are about 19 when it begins. Rossweisse's canon age in High School DxD is never stated, but heavily implied to be only a little older than Issei. I decided to highball it and make her 19, rather than the 17-18 she would be.

Oh, and Lily's in this too. Only, she's a bit different...

VALKYRIES AND DEATH GODS AND DEVILS, OH MY!

CHAPTER 1:

VALKYRIE AND DEMIGOD

Harry Potter woke up reluctantly. Not just reluctantly, but with a fog over his most recent memories, along with his mind. He wanted said fog to remain: something told him that amnesia was preferable to recollection. Sadly, memory is a treacherous and fickle bitch, not being there when we need it, and being there when we don't.

Soon, like water filling a glass, memory came back to him. The joyful memories of the past year. His friends and Dumbledore keeping him in the dark. The smear campaign in The Daily Prophet. The Dementors and the hearing. Umbridge. Snape and his so-called 'lessons' in Occlumency. The visions from Voldemort's mind, culminating in one with Sirius being captured, or so he thought. The running battle in the Department of Mysteries, all for a prophecy.

Then, Sirius hit by a curse courtesy of his cousin, the insane Bellatrix Lestrange. His staggering towards an archway. Harry rushing to save him, only to get knocked in in his turn. A moment of oblivion. And then, he woke up, to look around at the cave he had somehow ended up in.

It was cold, dark, and miserable. That was all Harry Potter really could tell about the cave. It seemed like a holotype of caves, and yet, there was something oppressive about the atmosphere. Like it was a place that nobody was meant to be happy in.

He certainly wasn't feeling happy. Was he in Hell? He thought Hell would either be much colder or much hotter. These caves were more uncomfortably cold, not the agonising torment he would have imagined, and in any case, he expected Hell to be hot, unbearably so.

Just his luck, then, to end up here, wherever it was. He didn't know what condition his friends and allies were in, and as much as he despised them keeping shit from him, he still cared about them. The Death Eaters were still attacking, for all he knew. Which was why he needed to find a way out of this.

Then, he began hearing voices in the distance. Voices that spoke a language he was sure he hadn't heard before, and yet, he could understand it. Three voices seemed to be speaking.

"…Down this tunnel." This was a woman's voice, and a maddeningly familiar one.

"My Lord, My Lady…should we not be cautious? If someone has breached Helheim, then…" This was a girl's voice, one that sounded like it was his age, and yet, strangely older-sounding.

"Pah! Don't be so uptight, Rossweisse! This is why you can't get a boyfriend!" This was an old man's voice, though he suddenly yelped. "Hey, what was that for?"

"You treat your lovely prodigy Valkyrie like that, and that's what you get. Her thesis on Trihexa and its seals was probably the most informative on the subject I have ever read, and yet, you're treating her not just as a lowly PA, but also as a butt of all your sexist jokes. All-Father you may be, but someone needs to ensure you toe the line."

"Pah! See if I ever come to visit you again! Besides, you said it came through the English Veil of Helheim, right? All those wizards do is chuck garbage and their prisoners through. Whoever it is should be a corpse."

"They are not. I am finely attuned to the presence of the living in my realm. Whoever it is is very much alive…and familiar."

Harry decided that that was his cue to flee, and surged to his feet. But even as he made to run, he slammed into a wall of energy, etched with magical symbols. "I've found him!" called out the girl's voice, before he heard someone running up to him. Oddly enough, he was helped to his feet. He shook himself out of his daze to behold a figure of beauty.

The girl was apparently about his age, but she had long silvery-white hair, with the faintest tinge of lavender about her. Aqua eyes peered at him appraisingly. Oddly enough, she seemed to be dressed in a bizarre, armoured dark blue leotard that did little to hide her buxom figure. Her eyes flicked up to see his scar. She frowned. "…That scar…" she murmured. "…I see…the English Veil…but this scar…" She reached out to touch it, only to withdraw her hand with a hiss. "…I should have known. You must be Harry Potter. I'm sorry for this, but my Lord and the mistress of this domain sensed an intruder."

"You recognise me?"

"Even in Asgard, we know of your reputation, even if it's doubtlessly the work of wizards inflating your reputation. Forgive me, I should introduce myself. I am Rossweisse, a Valkyrie in service to Lord Odin."

"And a dried-up old prude who couldn't get a boyfriend to save the world," remarked the old man's voice. Harry saw an old man with a beard as long as Dumbledore's, his face lined and lecherous, a monocle covering one of his eyes. When he saw Harry, though, he stopped. "…My word. I…how can this…? Hel, come over here, at once!"

"What is it, you old lech?" snapped a voice from behind the old man. "And stop dissing poor Rossweisse, she's only fifteen. They get married later in life these days, and…what is this?"

And then, she appeared, from behind the old man.

It was impossible. Harry knew it was impossible. Not the rotting, decayed half of her face. As horrifying as it was, it wasn't as impossible as the rest of the woman he was seeing. Red hair, an emerald eye, and features Harry knew all too well.

"Harry?" the impostor asked. "I…what is…oh, you bastard! You complete and utter bastard!"

"My mother loved me very much, thank you," the old man harrumphed.

"Not you, you poor excuse for an Aesir!" the impostor snapped. "…Father will pay for what he did. But never mind that. Harry…please, come here."

"No," Harry said. "You're not her. You can't be her."

"I think she is, brat. I think my head was fucked around with as much as her own is," the old man said. "I'm starting to get my own memories back, and that brat's going to pay. Anyway, I'm Odin, Ruler of Asgard, leader of the Norse Pantheon, and with so many titles, it'd literally bore you to death to hear them all. And this is Lady Hel, Ruler of Helheim, my granddaughter by adoption…and, thanks to a time where she decided to be human, your mother, Lily Evans. So, better lube up, brat, because this is looking to be a clusterfuck of epic proportions…"

Three years later, as Harry got breakfast ready in the kitchen of 12 Grimmauld Place, he reflected that Odin had understated matters when he said that in his usual crude manner. It took a long time for him to accept the truth, as complicated and fantastical it was, sounding like the fevered delirium of some hack writer's mind. Okay, so his life at Hogwarts was pretty unbelievable, but what happened after the Department of Mysteries was even more so. He wasn't like the White Queen from Alice Through the Looking Glass and believe six impossible things before breakfast. Hell, he had a hard enough time believing the three that now comprised a cornerstone of his very existence.

The first impossible thing: his mother, Lily Evans, was alive, well, and was the Norse goddess Hel. As in, the death goddess. The one who was the daughter of Loki, and had half a rotten face.

The second impossible thing: his mother had forgotten about him. Apparently Loki had used a sophisticated spell not unlike the Fidelius to erase his existence from the minds of his mother, Odin, and the Marauders, who had been in on the secret of her existence. Harry's little trip through the Veil had removed that spell, and Loki had fled once he realised he was to be subject to the wrath of his daughter and his adopted father.

The third impossible thing: the Norse gods were real, as was virtually every pantheon under the sun. Indeed, the world currently was blissfully unaware that there was currently a ceasefire between the three Biblical Factions. The Angels, the Fallen Angels, and the Devils were in an uneasy peace that was often on the verge of tipping back into a devastating war.

The Norse Pantheon had loose but somewhat friendly relations with those three factions. Hell, Odin often played poker with two of the four Devil Kings, as well as the Governor-General of the Grigori, Azazel, and the only reason none of the Angels did so was because they had issues with gambling. Harry had even met the Devil Kings in question, along with Azazel. Sirzechs Lucifer wasn't the sort of person you'd think of when you thought of a Devil King. He was warm, personable, and quite good-natured. Serafall Leviathan looked like a surprisingly buxom girl in her mid-teens, was actually millennia-old, and acted like a magical girl from anime. Azazel reminded him a lot of Sirius, and the two actually got along like a house on fire.

And speaking of those who got along like a house on fire…a pair of figures shambled into the kitchen, presumably from the study that they had commandeered. Both were familiar, even if he had only known one of them for a few short years. "Thanks, Rossweisse. I never would have thought of that particular rune sequence," Hermione said, the bushy-haired witch rubbing at her eyes.

"Ikke noe problem, Hermione," Rossweisse said, stifling a yawn. "Frankly, I'm just grateful to have someone to bounce ideas off."

"How late did you two stay up?" Harry asked with fond exasperation.

"Probably too late, but it's all so exciting," Hermione said. "I'm still annoyed that this isn't standard education in wizarding schools."

"The level I got to is not standard, remember, Hermione?" Rossweisse said, before yawning again. "I was seen as…boring and nerdy because I focused so much on my magic studies instead of going out on dates. Still, I doubt even the standard things they taught we Valkyries would be on even the advanced curriculum at Hogwarts, or any European magic school. Half of it would be seen as dark, even if it actually isn't, and the rest is too hard for them to comprehend without advanced mathematical skills, and while Arithmancy is good for advanced maths skills, well, they don't always apply it."

"I think you two could do with some food," Harry interjected, albeit gently. "I'd suggest caffeine, but how much did you have last night?"

"Probably too much," Hermione admitted.

Harry nodded, even as he reflected that it was better than alcohol, at least for Rossweisse. Last Christmas, Sirius persuaded her to have a drink, only giving her a low-alcohol bottle of lager. She became plastered after a single sip, and ended up firing off an array of elemental spells while ranting drunkenly about Odin and the various ways he could go fuck himself. Thankfully, the colourful display had been covered up as a fireworks display, but things were pretty hairy with the Ministry.

Not that they weren't anyway. Harry had disappeared through the Veil in full view of many, and his reappearance some weeks later aroused suspicion. It didn't help matters that Voldemort himself died, horribly and in agony, shortly beforehand, courtesy of a ritual his mother used on the Horcrux in his scar, and more than a few Death Eaters were gunning for Harry, sure he had something to do with it. That, and Umbridge.

Harry chuckled to himself at the thought of what Dolores Umbridge was going through in Helheim. Hell hath no fury like a woman scorned, but that was nothing compared to a mother's wrath kindled. Loki, wisely, had fled when he realised the spells he had placed on his progeny had failed. Umbridge thought her position would save her. She was wrong.

However, there had been a very tense confrontation at Hogwarts, where Harry and his mother had confronted Dumbledore. The old fool had also been under the influence of Loki, to try and subvert Harry's life. Needless to say, Dumbledore wasn't going to be on any Christmas lists anytime soon.

As he served up the food, Rossweisse opened her mouth, but not to eat any of the food. Before she could say anything, Harry said, anticipating her usual question, "Rose, no, I didn't get this food on sale, so please, don't ask again?"

"But frugality is important! Even with your fortune, you have to carefully manage it!" Rossweisse complained.

"Rose, when I say you take me on a shopping trip, I can't exactly tell people that you want me to accompany you to Oxfam shops and pound shops," Harry groaned. "My budget can handle an occasional trip to Harrod's, and the Goblins are good at managing my money. Seriously, you're lucky they respected you when you came in with my statements and discussed things with them. Anyway, just enjoy the food, okay? It's not like I'm buying out Heston Blumenthal's entire larder from his restaurants."

Rossweisse pouted, but she began eating, and she smiled, despite her earlier qualms. "Mange takk, Harry," she said, slipping into her native tongue again. "I wish your cooking skills didn't come from what those appalling excuses for humans did to you."

"It's in the past, Rose. Besides, Mum's dealing with them."

"Yeah…which reminds me, Harry, I'd like your mother's permission to visit Helheim again," Hermione said. "I'm nearly out of some of the potions ingredients from there."

"Sure. You're always welcome there while you still live, Hermione. All of my friends are."

"It's only polite to ask first."

"How true that is," came a familiar voice from the door. And there she was, Hel, Lady of Helheim, known to two of those present as Lily Evans. Her face looked normal, and indeed, she could remove the decay from her face, albeit with some magical effort. "And I appreciate the gesture, Hermione, but as Harry said, his friends are welcome in Helheim without needing to die first. However, there is a matter of grave import I need to discuss with Harry and Rose. Don't worry, you don't need to leave, it's not exactly a secret. I'd even value your input."

"What is this matter of grave import, Lady Hel?" Rossweisse asked.

"…Rossweisse, I keep telling you, call me Lily. Anyway…look, Odin didn't want to tell you himself, so he sent Muggins here to tell you because he's a coward. You do know he plays card games with some of the other faction leaders? Well, they often bet favours as the stakes…and Odin owes Sirzechs a favour. So, you'd better get your bags packed, you two. You're heading to Kuoh, Japan."

"Why is that?" Harry asked, frowning.

"As far as the Muggles are concerned, Rossweisse is the new Civic Studies teacher at Kuoh High School, and Harry will be 'special advisor', alongside Rossweisse, to their Occult Research Club. However, the Occult Research Club is a cover. Kuoh is a territory shared by the Gremory and Sitri families, administered by their respective heiresses, Rias and Sona. Your purpose there is going to be twofold. To act as the Norse Pantheon's ambassadors to the heiresses and their respective Peerages, and to train them and help them get stronger…"

CHAPTER 1 ANNOTATIONS:

And there you have it. Don't worry about the gaps in exposition, they'll be filled gradually as we go along. Still…Lily Evans is actually Hel? What the fuck?

No numbered annotations this time.