Sentry's Testament

by FanOfMostEverything

Rating: teen
Tags: Applejack (EqG), Random, Equestria Girls, Crossover, Flash Sentry, Slice of Life, Other, Rainbow Dash (EqG), Comedy
Length: 2576

Rainbow Dash and Applejack learn why you should never interrupt another band's practice.

The Rainbooms are one of the few bands at CHS that didn't dissolve after the fad passed with the Battle of the Bands. Of course, they aren't the only one. Flash Drive never stopped being a thing, which means Applejack and Rainbow Dash can borrow their guitarist to settle a bet. Should be simple, right?

To be fair, it was still early in the girls' career as magical guardians. They had yet to learn that nothing is ever truly simple.

Rated Teen for more teenager-y teenagers than EqG normally gets away with and offscreen mayhem. Written for CRACK-STORM 2020

Published 2020-04-01 18:30:02 UTC
Last updated 2020-04-01 18:30:02 UTC

F1S1

Flash Drive might not have been the best band at CHS, but it still existed, which was more than Flash Sentry could say for a lot of them.

He understood why most of the bands that had competed in the Battle had come apart as quickly as they'd formed. Students who didn't already have a passion for music just didn't want to invest the necessary time and effort into maintaining a band without some larger incentive, like showing off for the rest of the school. He didn't begrudge them either; he knew some people just didn't feel the same way about music that he did.

Sadly, one of those people who didn't was his bassist.

"Seriously, dude," Ringo said midway through an after-school practice session, "what is your secret?"

"What secret?" Flash said before he could stop himself. He verbally scrambled to get back on track. "Besides, we really do need to get this bit down—"

"Yeah, yeah, we'll get it. And you know what I mean." Ringo waggled his eyebrows, and the scraggly mustache he refused to shave wriggled on his lip like a balding caterpillar.

"I don't know what you mean," said Brawly Beats, who Flash's father had described as "a natural-born drummer."

Flash nodded. "I'm with Brawly on this one, dude."

Ringo put a hand on his shoulder, and Flash fought the urge to cringe. "Flash. My bro. My Broseph. My Empress Brosephine de Breauharnais."

"Never call me that again." Flash peeled the hand off like he was handling someone else's used tissues. "And get to the point, but mostly don't call me that again."

"Cool, cool. I mean what's your secret with the ladies?" Ringo seemed physically incapable of pronouncing that word any way other than "lay-dayyyys," and every time he did, Flash had to remind himself that they'd been friends since second grade, and breaking a friend's sunglasses with one's fist was generally frowned upon.

Flash rubbed his temples while working his way through that well-worn mental path. "I have no idea what you're talking about, dude."

"Come oooon." Ringo started ticking points off on his fingers. "Sunset Shimmer, demonic hotness. Twilight Sparkle, girl from another world who falls for you, literally. Lyra Heartstrings—"

"Lyra figured out she was gay because of me, dude."

"Still counts."

"Twilight..." Flash winced.

"What? If it weren't for Big-Mouth Lulamoon, you'd have made out with her on stage! That's the dream, man."

I'm sorry, Flash. It wouldn't be fair to either of us. I have duties in Equestria. You have a life to live here.

"Forget it, man," Flash said aloud. "We're from different worlds. Like, literally different worlds. It just wouldn't work out."

"And she's a horse," added Brawly. "'Course, so's Sunset, but... well, Sunset."

"Seriously, Ringo, you know what I went through with Sunset."

"Even I know what he went through with Sunset." Brawly shook his head. "Took both of us to convince him to break up with her, even after the Spring Fling."

Ringo shrugged. "My point is that's still three more girls than Brawly or I ever got."

"Dude! Wallflower's a sweetheart."

"Literally who?"

Brawly scowled. "Screw you, man."

That got another shrug before Ringo turned back to Flash "So how do we get some of that Sentry swag?"

"Step one, stop saying crap like 'Sentry swag.'"

"Fine, don't tell me."

Flash rolled his eyes. "You're blowing it out of proportion, Ringo. I don't have some magical girl-attracting power."

"Magic's real, dude." Ringo nodded in the direction of the Rainbooms' practice room.

Flash pointed to his own scalp. "And I don't sprout horse ears when I play."

"Maybe if we had a better songwriter..."

"Bedroom Spackling Project is my magnum opus."

"Dude," said both of Flash's bandmates.

"Okay, it sucks, but you've gotta walk before you can run. Now come on, we really should get the chorus down before—"

The doors of the practice room flew open, admitting a two-girl stampede. Rainbow Dash and Applejack charged in shoulder-to-shoulder, still shoving one another even when they were inside.

"Flash!" cried Dash.

"We need you!"

Flash glared at a smirking Ringo. "Not. A. Word."

"The results speak for themselves, dude."

Flash rolled his eyes. "What is it, girls?"

Applejack managed to settle herself in the meantime. She cleared her throat. "I mean, I hate t' impose."

"I don't," said Dash. "We need you to settle a bet."

Flash looked around and got a pair of shrugs. "Me?" he said, pointing at himself just to be sure.

Applejack hefted one of two instrument cases she'd hauled in with her. "Rainbow here says acoustic guitar ain't good fer nothin' but country music and curin' insomnia."

"And I'm right." Dash crossed her arms. "If you're not playing electric, you're crooning about how your girl ran over your dog while she took your truck. Or asking Harmony to punt you through the goalposts of life."

Applejack scowled. "Don't you badmouth Bare Bobbin. That man's a national treasure. Besides, acoustic can do a lot more than just country."

"Then prove it!"

"That's what I'm here for." Applejack opened the case. "Flash, I'm gonna need yer help on this one. Sunset don't know the song I have in mind, an' she said you taught her everything she knows."

Right, because obviously Applejack would have no other way of knowing Flash played guitar. He took a deep breath and said, "I don't know the song you have in mind."

"I'll play on bass. You should pick it up real quick." She opened the other case and started plucking away at a simple yet familiar melody. Flash was used to it at a faster tempo, but recognized it almost immediately.

"Wait, isn't this—"

"Hush now. I wanna surprise Rainbow." Applejack tilted her head towards her friend.

Dash just crossed her arms and leaned against the wall. "You haven't yet."

Flash sighed and picked up the guitar. A few strums to tune it, and he joined in, getting a feel for the chords.

"Someone wake me up when they're done," Dash said between yawns.

Applejack smirked at Flash. "Think you got it?"

He smirked back. There was only one proper response. "Hell, yeah."

They sped up to the usual tempo. The sound let Flash sink into memories. Spending a boring family get-together watching with wide eyes while an older cousin blasted bulky sprites until they sank into piles of gore. Buying the remake, better than it had any right to be, and wreaking havoc himself. Firing a pulse of ruinous green energy at the cackling she-demons that tried to curl their claws around his mind.

There was something off about that last one, but a surge of energy rushed through Flash's body before he could think too hard about it. He gasped as warmth filled his every cell and his confused mind tried to make sense of what just happened.

"Well, butter my backside and call me a biscuit." Applejack's countryisms didn't help. Neither did feeling his ears turn to better focus on her voice. At least she looked as confused as he felt. "Didn't see that comin'."

Brawly's jaw dropped. "Dude, your hair!"

"You look like a Dragonpearl character," said Ringo. "That even your final form?"

Rainbow Dash grinned like it was her birthday and Yuletide at the same time. "And you've got wings! Awesome!" Oh. That was what she was holding. "Dude, I gotta show you what you can do with those babies."

The rush faded, leaving Flash staggering like an adrenaline crash.

"Oh. Darn. But it should just take another rockin' solo to get 'em back, right?"

Applejack smirked at that. "Another rockin' solo, huh?"

Dash's face screwed up for a few moments before she sighed and said, "Okay, fine, you were right. This time. When the song's originally made for electric."

"Aw, come on, you..."

"Dude." Flash turned and blinked. How long had Brawly been by his side? "How you feelin'?"

"Honestly?" Flash looked at the guitar like he'd never seen one before. "Like I still have unresolved issues with Sunset."

"So... inner demons?"

"Shut up, Ringo."

"Practice over?" said Brawly.

"Practice over." Flash sighed and half-shouted to get through the bickering "Girls? I'm gonna need some tips on how to deal with Sunset."

They traded a worried look. Dash took a few steps back, hands up as though to ward off the drama. "Look, dude, I know we've got crazy horse magic running off the power of friendship and the power of rock, but that doesn't mean we're gonna step on that landmine."

Applejack jabbed her with an elbow. "What Rainbow means is it ain't our place t' meddle in a personal matter 'tween you two."

"Right, what she said."

"Fair." Flash looked back at the guitar. "Suppose I can at least try for a magical boost of my own."

Rainbow Dash looked nervous at that idea. Flash would recognize the warning sign in hindsight. "Uh, not sure if that's such a good—"

Chords flew in another track. The image of the cackling queens of the underworld and visiting righteous, plasma-fueled vengeance upon them returned. And rather than question it, Flash embraced it.

The change came again, enveloping him in power and certainty. Flash strummed his guitar with malicious intent. It thrummed at a frequency somewhere between a Mongoatian throat-singer and a chainsaw eager to find some meat. He nodded in approval and stomped out of the room, every armored footfall causing small but noticeable tremors. "Wish me luck."

The girls shared a panicked look and ran off after him. Ringo stretched and got up from his seat in a much more casual fashion. "This is gonna blow up in the faces of everyone involved. Come on."

"We're gonna stop 'em, right?" said Brawly.

"You can try. I just want to be there to record it."

With Dash and Applejack gone, the other Rainbooms had done some individual practice before putting aside their instruments and chatting. That came to a halt when an armored boot kicked open the doors of the practice room.

Rarity dropped her keytar and went into a ready stance, staggering only slightly as it tugged at the strap around her neck. Fluttershy hid. Pinkie provided a drumroll.

And Sunset just stared as a mysterious figure walked into the room, clad in deep blue armor with safety cone-orange accents. A mental voice that had gotten quieter over the months and nearly silenced after the Battle of the Bands screamed in her mind. Her guitar slipped out of numb fingers, and the shifting weight nearly sent her sprawling to the floor.

Perhaps it was the motion that made that helmet turn towards her. She couldn't see through the faceplate, but she knew, down in the deepest, darkest pits of her soul, that the being within was looking right at her.

Sunset had courageously faced conjured monstrosities of the Outer Planes, sirens bent on world domination, and the School of Gifted Unicorns academic probation board. But against this figure, this titan of unbreakable determination and barbarous intent, she felt nothing but fear.

"They did it." She fell to her knees, ready to beg or plead or offer worship in vain hopes of placating the implacable. "The battle was too big, too flashy. They've come for me."

"Darling," said Rarity, sidling up to cover Sunset's right flank, "we've been over this. No one is going to stick a black bag over your head and cart you off to Hoswell. And I have studied every uniform in our nation's armed services for school projects; I assure you, that is not an FSA soldier. And the wings are something of a giveaway in and of themselves."

"Wings?" Sunset hadn't even noticed them. They were folded against the being's back, largely obscured by the armor. Armor worn in the First Age, gibbered the guttural voice in the back of her head, in the First Battle, when the shadows first lengthened...

"Hi, Flash!"

"Hi, Pinkie."

"Huh?" The response had been muffled by the helmet, but there was no doubt who'd said it. "Flash Sentry?"

The voice of Sunset's inner demon faltered. Then it panicked even more incoherently.

"Guys! Flash got magic from rocking out and now he's..." Rainbow Dash trailed off as she took in the scene. "Oh."

"Sunset," said Flash, still gazing at her as neutrally and terribly as Princess Celestia at her most disappointed. "We need to talk."

"Uh..." Sunset swallowed against her dry throat. "We already broke up. You were very clear on the matter. And then shared the only piece of blackmail I could ever get on you on MyStable just to make sure I could never get back at you."

"I don't think still having a stuffed bunny is anything to be ashamed of," Fluttershy murmured from behind cover, which in this case meant the practice room's piano.

Flash shook his head. "We never faced off in the Battle of the Bands."

Sunset blinked. "Wait, that's what this is about?"

That got a single nod. "This Saturday. The gazebo in the park. Flash Drive versus the Rainbooms."

After a look around the room to confirm everyone else was as confused as she was, Sunset gave an uneasy smile. "Um, sure?"

"Good." He made to turn, but paused. "Oh, and one more thing." A device mounted to his right shoulder turned and fired a yellow-orange laser at Sunset. She winced, then gasped as it hit something buried deep within her. A silent scream deafened her, and she fell onto her back.

A dark blue shape leapt over her, blurred by both speed and her hazy vision. Screams and grotesque, organic snapping filled the room for a few seconds before Flash came back into view, dusting off his hands.

"No need to thank me." The armor and wings evaporated into magic sparkles, and Flash gave that perfect little smile of his. "See you Saturday."

"Dude!"

"Duuude!"

"Dudes."

Sunset just stared at the ceiling for a while. Finally, she managed a "Wha' happen?"

"Flash shot your shadow!" Pinkie said with her usual cheer.

"It tried to dodge. And, um, didn't. And then he..." Fluttershy trailed off, looking green.

Applejack helped her sit up. "Are you alright, Sunset?" asked Rarity. "How many fingers am I holding up?"

"I don't have a concussion, Rarity. I'm pretty sure Flash just destroyed the last trace of the she-demon with both incredible brutality and surgical precision." Sunset felt herself blush. "Is... is it wrong that I'm a little turned on right now?"

"After that display?" Rarity smiled and patted her hand. "Darling, Lyra and Bonbon would be left a tad hot under the collar."

Dash looked around the room. "So no one else is gonna say it?" She beamed, so delighted her wings manifested and spread without her even playing a note. "Dibs!"

Author's Note

And those who heard the licks of his axe named him... the Waifu Slayer.

So yeah, been listening to riffs on the Doom soundtrack, and, well...

Yeah. That seems horse-magic-worthy. Though combining it with the memetic resonance of annihilating the legions of Hell may have some unforeseen side effects.

Bedroom Spackling Project comes from scoots2's The Looking Glass World of Cheese and Pie, still my go-to source for Flash Drive song names.

And yes, Bare Bobbin is based on a musical artist of our world. Likewise that song.

Not exactly an April Fool's story per se, but I'm still happy with the madness.