Lux-Umbra Magna Auguratricis is a The Loud House fanfic written by Exotos135, the same author of The Loud Sim Date and Chains of Reality
The summary reads as follows:
"Royal Woods is changed forever when monsters called "Shadows" attack the city, and with the help of a creature known as "Gemini," the Loud Sisters become magical girls to combat the threat."
It can be read here: here
Now has a sequel can be read here
This fanfic has examples of the next tropes:
- 11th-Hour Superpower: In order to defeat Dawning Dusk, Lily and Girl Jordan achieve one such power by entering the Twilight Word, and being knighted into becoming World Auras.
- 12-Episode Anime: The basic structure of the story and it's use of multi-part episodes is based on this, as 24 chapters are divided into 12 episodes, two chapters for each episode.
- Abandoned Laboratory: The laboratory Lincoln and Lisa used to work at has understandably been abandoned, seeing as its former occupants have gone missing. Even after Gemini and Divisu are revealed to be Lincoln and Lisa, and Leni is revealed to be in cahoots with them, the laboratory is still relatively abandoned, only housing the cocooned project.
- Action Girl: The Loud sisters, and the Lux Auras as a whole, considering that they need to be this in order to fight against Shadows.
- Another Dimension: The Twilight World is an alternate, completely monochromatic dimension that also houses creatures similar to Gemini and Divisu, and also happens to be the birth place of every Shadow and Eclipse ever encountered.
- Asshole Victim: Tetherby and his group took advantage of Lincoln and Lisa's need for help for the project, then turned it into a doomsday weapon with no care for the consequences. Said doomsday weapon creates Dawning Dusk, who promptly absorbs his and his group's essence into herself. While you could argue whether the group deserved the fate, Tetherby most certainly did.
- A Truce While We Gawk: When Lily and Girl Jordan return from the Twilight World as World Auras, both the Shadow/Eclipse and Twilight Army stop what they're doing to watch them in shock. Once the fight resumes, the latter quickly overpowers the former.
- Awful Truth: While Lincoln and Lisa did go missing, they were actually nearby the whole time. More accurately, as Gemini and Divisu, respectively.
- Beam-O-War: One of these takes place between Lily and Girl Jordan in their World Aura forms and Dawning Dusk in a desperate attempt to finish the apocalypse once and for all. While initially stuck on a standstill, and with Dawning Dusk initially winning said standstill, Lily and Girl Jordan gain enough power to overpower Dawning Dusk, sending her straight into the Twilight World.
- Big Bad Duumvirate: Initially it seems Gemini and Divisu are the main antagonists, since they're the ones responsible for the project, but then it turns out that they work for Tetherby and his group, meaning he and his group share the big bad role with Dawning Dusk, the project in question, who comes out just in time to destroy the world.
- Bittersweet Ending: Royal Woods has been saved from Dawning Dusk, and every Lux and Umbra Aura has been turned back to normal without having to worry about Dawning Dusk getting out again. However, the portal to The Twilight World has been closed, meaning Lincoln and Lisa, as well as Tetherby's group, are forever closed off from receiving proper punishment for their actions, with Leni deciding to take the brunt of it so she can pay for what she did, too.
- Bond Creature: Gemini, which is the way that they create Lux Auras. There's also another creature known as Divisu, but they don't exactly have to go through the same bonding process...
- Book Ends: The first chapter begins with Lily being visited by Gemini during a dream. The last part of the final chapter is Lily being visited by Lincoln and Lisa's energy forms while in the same dream state. Furthermore, both the beginning and end of the first chapter had narration, and before "The End" shows up, a little bit of narration also pops up to tell us what happened since Dawning Dusk's defeat.
- Canon Character All Along: Gemini and Divisu are transformed versions of Lincoln and Lisa.
- Contrived Coincidence: Part of Girl Jordan's reasoning for distrusting Gemini is the fact that they appeared not only when the Shadows appeared as well, but when Lincoln and Lisa went missing.
- Conservation of Ninjutsu: Inverted with the very first fight in the story. Lily faces the Shadow alone, and winds up getting trashed, but as soon as the rest of the sisters show up, the Shadow's beaten with little problem.
- The Corruption: Chapter 6/The second part of episode three involves Dana being tempted by Divisu in order to become something like a Lux Aura, but kind of different. And not in a good way...
- Crystal Prison: A rare defensive example. Dawning Dusk's capsule, once enough progress has been made, is encased inside an indestructible crystalline object that not even three Twilight Auras can't break with all their might.
- Cutting the Knot: This is actually part of the Lux Auras job: The Shadows come from cores of darkness, which go from antumbra to penumbra to umbra, then transform into a Shadow. Therefore, it's the Lux Aura's duty to find these cores when they do pop up, and stop them from turning into the Shadows.
- Dark Is Evil: The Shadows, and consequently, their cores of darkness. It's the Lux Auras jobs to destroy the former should the latter fully blossom, and destroy the latter before they turn into the former.
- It's this trope that gives the Umbra Auras a rather pessimistic existence, since until Lily gives Girl Jordan the idea that she doesn't have to be evil, every other Umbra Aura besides her and her group seem to have chosen to follow this idea out of principle.
- Dark Is Not Evil: Discussed. Lily points out to Girl Jordan that just because she's an Umbra Aura doesn't mean that she has to be evil. While she has a bit of trouble coming to terms with this idea, she eventually decides to give it a go, and confirms that yes, she doesn't have to be evil. Nor does her group.
- Dark Magical Girl: Girl Jordan, at least when compared to the other Lux Auras. Becomes an even more literal version of this trope when it turns out she's actually an Umbra Aura, the dark counterpart of the Lux Auras.
- Deliberately Monochrome: The Twilight World as well as the form handed to those knighted inside it, The World Auras.
- Domed Hometown: Dawning Dusk encases Royal Woods inside a dome after sending a de-powered Lily and Girl Jordan out of the boundaries. One chapter later, it gets broken.
- Eldritch Abomination:
- The Shadows are pretty much this, going by the giant, massive one that opens up the story. They're created from cores of darkness that appear periodically across town, which if not taken care of, will transform into Shadows.
- The Eclipses are an even better example of this trope: Most of them generate a massive dome, known as the Shadow Zone, with their presence, and things inside of it can range from normal to absolutely weird. Not to mention that, even compared to the Shadows, they tend to look quite bizarre.
- I Will Find You: This is part of the Loud Sisters, and Lily's, motivation as Lux Auras: To find their missing siblings, Lincoln and Lisa. They eventually find them... but not in the same way as they used to be.
- Knighting: Happens twice to Clyde: The first one is done to turn him into a lux squire, and the second turns him into a knight, and lets him use the light sword. Then a third one happens for Lily and Girl Jordan, as they're knighted by Lincoln and Lisa in order to become World Auras so they can defeat Dawning Dusk once and for all.
- Light Is Good: The Lux Auras, allegedly Latin for Light Auras, are the magical girls that protect Royal Woods from the threats of the shadows and their cores.
- Light Is Not Good: Lincoln, one of the two main antagonist of the fic along with Divisu. There's also the fact that a Lux Aura who's incredibly angry at someone can cause some great damage, like Becky.
- Made of Indestructium: The cocoon that Lincoln and Lisa's project has surrounded itself with is strong enough to tank direct hits from three adult twilight auras.
- Magical Girl Warrior: While the summary outright describes the Lux Auras and the Loud Sisters as magical girls, in practice, they're more along the lines of this trope, since magic is used very sparcely, if at all, and most of the fighting consists of swinging their weapons.
- Multi-Part Episode: A weird variation, since technically every pair of chapters are really just two halves of a whole episode (Chapter 1 and 2 form Episode 1, Chapters 5 and 6 form Episode 3, and so on), but there are also chapters that are explicitly titled as multi-parters, like "Eclipse" (Chapters 7 and 8) and "Revelation" (Chapters 11 and 12).
- Older Is Better: There are implications that auras made from adult women are stronger than those made from teenagers and children: Mrs. Johnson quickly turns the tide against Dana's Eclipse form, and defeats Leni, someone who the entire Loud sister team and Clyde couldn't beat together.
- Sibling Team: The Loud Sisters, naturally, work as a mostly single unit when in Lux Aura mode. Some tend to go off and do their own individual thing, but for the most part, they work together.
- Stating the Simple Solution: This is part of Gemini's explanation in chapter 2 when the sisters question why they have to destroy the cores: Since the cores turn into Shadows if allowed the grow, destroying the core destroys the Shadow before it even gets to be a threat.
- Sword of Plot Advancement: The Light Sword Clyde gets plays with it. On the one hand, the plot was moving at a decent pace before the sword came into play, but on the other hand, the sword forces Divisu to come out of Teri's possessed body, avoiding getting the story stuck on a stalemate.
- Transformation Trinket: Light Cubes for the Lux Auras.
- World-Healing Wave: After Dawning Dusk is defeated, the beam that took her to the Twilight World explodes, unleashing a wave that not only closes the portal between worlds, but also heals the destruction caused to Royal Woods.
- You Can't Thwart Stage One: In two forms; In the first, Lincoln and Lisa manage to unleash Shadows to distract the auras from finding and destroying their project, and in the second, the project has surrounded itself in a crystal cocoon by episode 9/chapters 17 and 18 that can't be destroyed even with the powers of adult twilight auras.
