The memory was still fresh, even after all these years.

A black sky and a black world, consumed by fire. The smell of burnt flesh pervaded his nose, and the sound of the dying invaded his ears. The fire came like a tsunami, consuming everything in its wake. People died in the flames. People died trying to rescue their loved ones. In this ash-filled wilderness, a lone boy walked, ignoring the pleas of help from those around him. He walked, until his eyes and his legs gave way.

In that moment, the boy surrendered himself to his fate.

Chapter 7
The Measure of a Magus

"Rin, this is wrong! So wrong! And dangerous!" Ruby Rose said, her small hands waving in the air.

"Relax, I know what I'm doing." Rin said with a smile, her arms crossed over her chest.

"The last time you said that, a Dust crystal exploded in your face." Weiss pointed out, sitting on a chair on the opposite end of the room.

Five girls were currently gathered in one of Beacon's many chemistry laboratories. Two of the girls, the oldest and the youngest respectively, were dressed in white lab coats. The others were dressed in their school uniforms. Said others were also a significant distant away from the former two.

The blue-eyed magus raised a Dust crystal to the room's fluorescent light. The crystal was significantly larger than the earlier crystals she experimented with. These crystals however were of a higher quality than the lab samples she normally uses. These crystals were considered to be ten times more powerful than their smaller counterparts, and were specifically used in and as ammunition.

"Rin! Seriously!" Ruby, who has taken the role of her unofficial chaperone in Beacon, said with another wave of her hand. "At least consider using Wind Dust instead."

"Wind?" Rin thought for a moment, glancing at the red crystal between her fingers. "Wind… are those the green ones? I was only able to get samples of Red Dust, but I'll think about using greens in the future—"

"Riiiin." Ruby whined.

The magus sighed and lowered the Dust crystal. She approached Ruby and smiled, placing a hand on the younger girl's head.

"Trust me, Ruby. I know what I'm doing."

She let go of the pouting girl and approached an empty table. Placing the Dust into the center of the table, in the middle of a hand-drawn spell circle, she closed her eyes and began.

Channeling magical energy into the crystal was a simple affair for a magus of Rin Tohsaka's caliber. Manipulating the strange mineral was different from manipulating jewels, but the basics were similar enough. In a matter of one week, she was able, through much trial, error, and explosions, learn the very basics of activating Dust. Though she focused mainly on one element due to limited resources, she has at least been able to successfully activate and more importantly stabilize Dust crystals.

Now, she was attempting something a bit more advanced.

The crystal began to glow and her assistant-slash-team-leader took a cautious step back beside her. Magical energy poured from her internal reserves into the alien rock, causing it to burn the color of vermillion. The crystal began to pulsate and glow and everyone in the room, save for Yang, noticed an increase in temperature.

Just when Ruby expected another disaster to happen, the crystal's glow began to fade. Rin performed the final steps of her experiment, the magical energy she poured into the mineral weakening, trickling down like a faucet slowly being closed.

With a loud, sigh, she released her hand from its position above the crystal and stepped back.

"I did it." she announced.

"What exactly did you do?" Ruby asked cautiously.

"I have successfully made a magecraft-fueled Dust grenade." Rin beamed. "At least I think I did. It's set to explode in ten minutes, maybe more, maybe less. But the point is, it didn't explode right away. Speaking of which, how do we get to the firing range?"

Everyone else in the room immediately raised their Aura.

[—

Shirou sat under the shade of the Meryrose Tree, his arms behind his head. In the distance, his unofficial teammates were in the middle of a two-versus-two spar, with Ren and Pyrrha facing off against Jaune and Nora. The magus figured that it would have been a much better format if it was a three-versus-one instead— Pyrrha was easily superior to the rest of her teammates— but decided not to mention it.

A shadow fell on him just as he was enjoying the afternoon breeze. Turning to the shadow, he saw Rin standing with a vase in her hand.

"My gradation air just evaporated." she said, sitting down to Shirou's left. "Yours is still as solid as ever, but mine lasted a good two days. Way longer than it normally would have back home."

She placed the vase on the grass and poked it with a finger.

"How are your other projections doing?"

"They're still back in the dorm room."

"All of them?"

"Yes."

Rin placed a finger to her chin and closed her eyes. "That's… impressive. Even the first ones you traced? How long ago did you trace them?"

"We've been here for three weeks… so, yeah. Three weeks."

"That's insane, even for you."

"What can you draw from this, then?" Shirou said, reaching forward and picking up his projected vase.

"Well, this basically just confirms one of my theories, even though I've basically already confirmed it before." she leaned on the same tree, crossing her legs. "Our magecraft is stronger here, by a pretty significant margin. Maybe three or four times stronger. But it's stronger not in a numerical sense, but more in an 'effectiveness' sense."

Shirou nodded, not saying anything. He knew that Rin was about to explain her thoughts to him.

"At the very least, this confirms that this world has a Gaia equivalent. Something that attempts to counteract the magecraft we perform. But seeing that, hopefully, we are the only practitioners of magecraft on this planet, the miracles that we create are a great deal more effective than they otherwise would be.

"I did a bit of reading, and while there isn't a solid number anywhere, theories place the combined population of this world at around two-hundred-million."

"That's much smaller than Earth's." Shirou pointed out.

Rin nodded. "Yep. Just a bit smaller than America's population, I think. Anyway, ten-percent of that is composed of people who are good enough to pass basic combat schools, like Signal. Of course, only ten percent of that is maybe good enough to actually graduate into professional huntsmen, but that's beyond the point. That's still twenty-million people capable of using their Auras efficiently. We can also guess that a similar, but smaller number to that can use their Semblances effectively.

"Yet despite these impressive numbers, our magecraft still functions at peak performance, or rather, into overdrive. Based on this, we can assume that this world's Will doesn't consider Auras, Semblances, and other native abilities as foreign concepts that need to be eliminated or controlled."

The pair spent a few moments in quiet contemplation. In the distance, the sound of clashing blades and training bullets buffering against Jaune's aura filled the air.

"What exactly did you mean by our magecraft being more effective here?" Shirou asked.

Rin considered her answer before speaking. "Well, basically, any magecraft we do is just better, in some ways, at least. In theory, projections should last longer, and alchemy should be more potent."

"That explains why your Gandr is so strong." Shirou pointed out.

"I haven't really considered that." Rin smiled. "Finn Shots are already considered powerful, but I was surprised that one of my Finn Shots was strong enough to tear through a Boarbatusk's armor. Apparently those things are one of the tougher types of smaller Grimm. In theory, the same should apply to your broken phantasms, though I'm not sure if we should be testing that anytime soon."

"But I'm surprised. I don't feel my spells costing more prana than usual." Shirou said.

"Probably just an aftereffect of our contract." Rin considered. "That also explains why we haven't noticed these things sooner." she reached into her pocket and produced a couple of Dust crystals. "Also, take a look at this."

"Those aren't going to explode any time soon, are they?"

"No, of course not." Rin said, a bit too defensively. "I'm showing you this, because these are the first crystals that I've been able to activate. This green one corresponds to air, the two red ones are fire, and the blue one responds to water. These are, at least, the basic types of Dust. Other types are formed by combining these four."

Shirou picked up the curved green crystal and examined it. "What happened when you activated them?"

"I've been mainly focusing on the red ones. This green and blue crystals are the last ones I have. The green crystal released a small gust of wind, the red crystal released a small gout of fire, and the blue crystal accidentally sprayed Weiss with water."

"Accidentally?"

"Accidentally." Rin cleared her throat. "It took a bit of practice, but the process is surprisingly similar to reinforcement. We can't just haphazardly juice these things up with prana. A bit of actual spellwork is necessary." she smiled and returned the crystals into her pocket. "While I'm still unable to come up with more creative ways of using these, I'm definitely going to continue experimenting. In a week's time, I should be able to use Dust crystals as substitutes to my gems."

"Jewelry still exists in this world, Rin." Shirou pointed out. "If you want, we can go buy some the next time—"

"Nah, let's not bother, at least for now." she shook her head. "High quality gems are as expensive here as they are back home. We're better off spending your salary on more practical things. Low quality gems wouldn't be that much of a step up compared to Dust crystals."

Shirou realized something, in the distance Nora flew into the air from one of Pyrrha's attacks.

"How are you planning to use these crystals? By throwing them at people?"

"Well, that's how I normally do them, so yeah." Rin narrowed her eyes. "You're thinking I should use something like a weapon, aren't you?"

Shirou shrugged.

"Weiss uses a lot of Dust in combat, but Myrtenaster uses powdered dust, not crystalline. Save for that one kid on CRDL, everyone else uses Dust mainly for ammunition. Though I'm pretty sure there other caster-type people in higher years. I think I'll stick with my old style, for now." she grinned. "At the very least, I can still make these things explode."

"Have you tried infusing spells into them yet?" Shirou asked.

"Oh no, no, not yet. Well I did. But they uh, exploded. So we're not trying that anytime soon."

Shirou considered, nodding his head. He opened his mouth to talk, when he heard JNPR approaching, having finished their team-oriented spar. Pyrrha and Nora waved at the duo as they approached, with a silent Ren and a battered Jaune following close behind.

"Anyway, I think that's all we need to talk about for now." Rin said, smiling back at the two redheads in the distance as they approached.

[—

It didn't take long before Shirou and Rin developed a daily routine.

Rin spent most of her days acting as a stereotypical student. She went to her classes, studied in the library, experimented on Dust crystals, and would occasionally bother Shirou while he was off helping someone in the school with one of their problems. The next day, just as the sun was beginning to set, she found him cleaning one of the vacant sparring rings. The redheaded magus was mopping the floor, not at all looking bothered doing a job that some would consider boring.

"Hey," she greeted as she approached, her stylish handbag slung over her shoulder.

Shirou smiled at her. "Give me a few seconds, I'm about done."

Rin sat down on a vacant seat, crossing her legs as she Shirou went about his business drying the mop. She produced from her bag a small stack of pastries, bought from a bakery just outside the campus. In it were tarts and cookies, too many cookies in fact, courtesy of a particular huntress in training.

After a moment, Shirou sat beside her, a sweaty towel over his head. Rin popped a cookie in his mouth, as she produced her scroll. With a bit of hesitant fiddling, she brings up a saved news article, published locally and distributed through Vale's kingdom-wide network.

"Wow Rin, I'm surprised you're actually using your scroll." Shirou quipped.

"Shut up." she held up the device. "Look at this. Have you seen this?"

"White Fang." Shirou narrowed his eyes, skimming through the article. "Sounds like a terrorist group."

"Well, they are a terrorist group." Rin said. "Composed mainly of Faunus, this world's resident oppressed citizens. They're apparently fighting for a cause, for the equal rights of their fellow Faunus or something."

"It all sounds very noble." Shirou said hesitantly. "But these things that the media is saying about them, it's all very disconcerting."

"Even the noblest cause can be twisted into something ugly." Rin said poetically. "Whatever the case, these fools are causing violence and destruction in most of the things they're involved in. If they keep this up, they're going to be just a big a threat as the Grimm."

"Do they have a presence here in Vale?"

"They have cells everywhere. So yeah, probably." Rin shrugged. "Regardless, I'm not happy with these guys. I can relate to their cause, but the amount of rampant destruction they're causing is something that doesn't sit well with me."

"That's unfortunate."

"This world has its own policemen, its own anti-terrorist forces. But this White Fang is an enemy we obviously need to be wary of." she scrolled down the article and pointed at something on her scroll's screen. "With this Vytal Festival coming up, it's practically guaranteed that the White Fang is try something."

"I quite like it here." Shirou said drily. "Maybe we should do something about it?"

Rin popped him a toothy grin. "I often gave you flak for trying to act the hero, but in this case I'm with you."

She stood up and slid her phone into her pocket. "But seeing that the festival's still a month away, we have plenty of time to first get a feel for this new enemy. Now, I don't really know what kind of crap the Faunus have to deal with, since I mostly hear about it secondhand, but I do know someone we can talk to."

A/N: A pretty short chapter this week, but mainly because I've been busy. We'll get into some White Fang shenanigans next week, maybe with a pint of drama thrown in.

Silentstrixe: Thanks. I'm trying to find a good balance between slice of life and plot in this fic.

TH351L3NTA55A551N: To be fair, it's probably going to take a while before Shirou's in a situation where he'll need to use an actual NP on anything.

Kaioo: It's just something in my headcanon. And I just decided to put it in because I thought it'd be sorta funny.

AzureStorms: Future chapters will hopefully feature POVs from native RWBY characters instead of being more Shirou and Rin centic.

Knight of the Iron Hammer Vita: I won't answer either question, but to be honest, even if Shirou manages to one shot the Grimm Dragon, it's not like that's going to solve everything. I'm trying to maintain a good balance between Shirou and Rin's general overpoweredness and a level of tension. As powerful as they are, they still won't be able to be everywhere at once. Also, the villains will soon no doubt learn about them, and may even adjust their plans appropriately.

Crazie194: I'm still not sure how I want to handle Shirou tracing RWBY weapons, but it'll probably along the lines of 'He can do it, but it won't be too practical because of mana cost.'

Guest: Sorry man, I'm not even aware Medusa Lily existed. o:

Server Lock: Girl-in-tank is canon to RWBY. She first appeared in Volume 3.

Ideagetthe: I will neither confirm nor deny this.