Flash is seen outside of his office building flipping the sign on the door to close as he is closing up shop for today as he’ll be at the Battle of Band final round with everyone, though he was hoping Sunset would come back by now to walk with him. Although, it would make sense for her to be with the girls to keep an eye on them in case the Dazzlings try anything on them, but he’s still worries.

“Odd, Sunset should’ve been back by now.” Flash said, getting a weird feeling about this.

Then he heard his phone playing the “Devil Trigger” ringtone, he pulls it put of his pocket seeing the caller ID is Sunset.

“Hey Sunset, where are you? Practice taking longer than expected?” Flash asked.

“No, we have bad news: Trixie trap me and the girls under the stage and we can’t get out!” Sunset informed.

“What?” Flash gasped.

“I think it must’ve been the Dazzlings though I’m not sure why.” Sunset said.

“Alright, I’ll be there as soon as I can.” Flash nodded and hangs up.

Flash ran as fast as he could to the Amphitheater, checking his watch to see that the final round of the Battle of the Band is about to start any second now. Then he unknowingly ran past Spike and a girl with him.

“Flash, over here!” Spike called out.

Lucky for the talking dog, Flash was able to hear that and made a sharp U-turn running back to Spike.

“Spike, what are you doing here?” Flash asked.

“I wasn’t caught in the trap with the girls, so went to go find you and another who wasn’t under the sirens’ spell.” Spike gestured to the girl next to him.

She has white-light yellowish gray, moderate cobalt blue with brilliant opal stripes, and wears cool-looking shades of gradient from dark purple to moderate heliotrope. She wears a zippered white shirt with blue lines on the shoulders to the short sleeves and at the bottom to the waist area, white skirt that is halfway to the knee with a single black music note, skinny violent pants with pink-purple lightning bolts, blue shoes with a sky-blue stars and white stripe. Breasts sizes: F-cup.

“Vinyl Scratch! You can resist the sirens’ spell?” Flash shocked.

“Headphones.” Vinyl said simply, pointing at her headphones on her head.

“She never takes them off.” Spike smirked.

“Oh, that makes more sense.” Flash chuckled.

Soon, the three made their way to the Battle of the Band final round to help free the Rainbooms and stop the Dazzlings.

(Amphitheater)

Flash, Spike, and Vinyl made their way to the Amphitheater where they see the Dazzlings are already on stage starting their song and seeing the green mist too, but Flash can tell this feels different than the others.

“Right here!” Spike pointed at the backstage door.

Flash quickly grab the door by the frame and rip it right open showing all seven girls including his girlfriend are okay.

“Twilight!” Spike jumped into her arms as she is happy to see him too.

“Sorry I took so long. I had to find somebody who wasn't under the sirens' spell to help me get you out and Flash was coming as well.” Spike explained and gesture toward Vinyl.

“Why isn't she under their spell?” Twilight asked.

“Never takes off her headphones.” Spike and Flash answered at the same time and Vinyl gave them a thumb up.

“So, the Dazzlings planned to trap you guys here.” Flash figured.

“Yep, causing them to argue for the Dazzlings to absorb their magic which means they’ll be harder to beat.” Sunset informed as Rainbow Dash walks up to Flash.

“Flash, look, I want to say that I’m… I’m sorry about the way I’ve been acting.” Rainbow Dash apologized.

“It’s okay, everyone can be like that when they want to big names for themselves and can get too caught up in them.” Flash said, forgiving Rainbow Dash.

“Come on, y'all! Time to prove we've still got the magic of friendship inside us!” Applejack determined.

“And there's only one way to do it!” Twilight smiled bravely.

“We're getting the band back together?” Pinkie asked.

“We're getting our band back together!” Rainbow Dahs nodded and Pinkie squeals in excitement.

“Ooh, which version of the counter-spell are we going to play?” Rarity asked Twilight.

“I don't think it matters what song we play, as long as we play it together as friends.” Twilight stated.

“I know just the song.” Rainbow Dash proclaimed, making the others worry a little until she walks up to Fluttershy.

“Fluttershy's written a really great one.” Rainbow Dash said, making Fluttershy feel so happy that she is squealing softly.

“We're about to save the world here. Personally, I think we should do it in style. Rarity?” Applejack asked.

“I thought you'd never ask!” Rarity pulled a clothing rag with all her music rock clothes she made.

Then Flash felt a familiar and dark presence around the Amphitheater, more like above them.

“No, you girls got get ready to play, I’m going hunting.” Flash said.

The girls nodded as they didn’t need Flash to tell them about another demon attack might by close by and trust him to handle it, they quickly ran to the hill a little far from the stage while changing into their rocker outfits.

(Music: Welcome to the Show, Equestria Girls Rainbow Rocks)

The Dazzlings are singing high and beautiful dancing together as they are about to unleash their plan.

Meanwhile, on top of the dome stage right above the Dazzlings, Arkham is looking down at the sirens and holding his crystal ball that is now all black and foggy of all the negative energy it gathered.

“Yes, sing to your hearts content… to serve me.” Arkham smirked.

“I thought I find you here.” Flash glared standing ten feet away from him.

“Flash, you’re just in time to witness the big finale I’m about to unleash.” Arkham greeted.

“A finale the Dazzlings have no idea about.” Flash guessed.

“Those fools only played along with me because I promised them to make their magic more powerful than ever, which is mostly true… and they’ll obey me as mindless slaves.” Arkham revealed his plan.

“So, that’s your endgame and about their mom?” Flash asked.

“Nevan, yes, those girls are never fond of her even though they’re not blood related. I also knew she would get in the way, so I had her… occupied at the moment.” Arkham grinned evilly.

The Dazzlings have begun their transformation like the Rainboom of their pony-up transformation, except their got fin-like wings and glowing red as they float a few feet above the ground.

Then suddenly, they heard another music being played from afar and loud as they look up at the hill seeing the Rainbooms playing their song.

“Sorry, but it looks like you’ll have to cancel that finale of yours.” Flash said and charge at Arkham with his sword only to clash against Arkham’s red demonic sword.

Their song has started breaking everyone free from the Dazzlings’ spell while Flash battles Arkham as they move around a little in circles. Arkham trip Flash and was about to slash at his back, but suddenly a lightning bolt shot knocked the cloaked boy away and they turn to see Nevan herself.

“What?” Arkham shocked.

“Did you really think a few worthless demons would keep me a bay, so you can harm my daughters?” Nevan asked sarcastically and angry.

Flash quickly move to Nevan’s side while pointing Rebellion at Arkham.

“So, you’re the Dazzlings’ mom. I can see where they got their sexiness from.” Flash complimented.

“And I know about you, Flash Sentry. Explanation will have to wait though.” Nevan glared at Arkham.

Now the Rainbooms have started their pony transformation with some new additions as they play their music together. Flash and Nevan work together fighting against Arkham to overpower him as he is force on the defense and moving toward the edge.

“So, the Rainbooms want to turn this into a real Battle of the Bands? Then let's battle!” Adagio glared determine to beat those girls once and for all.

“Yes, just what I was waiting for!” Arkham smirked and threw the black crystal ball down to the Dazzlings.

“No!” Nevan gasped trying to reach out for it, but too late.

The crystal ball shattered on impact releasing the negative energy it was stored along with some dangerous demonic energies too, the Dazzlings gasp upon seeing this and groaning in pain as the demonic mist is consuming them. Transforming them into bigger about 20 feet tall with mermaid tails, their eyes glowing viciously red, fish scales appearing on their bodies, nails growing into claws, teeth sharpen into fangs, and their wings becoming bigger and wider with few holes in them. And their breasts have grown as well into N-cup.

“Uh, was that part of their plan?” Rainbow Dash freaked out.

“I don’t think, it must be Arkham wanting to control the Dazzlings all along.” Sunset revealed.

“Then that means they were just being used from the start of all this.” Applejack added making the others shock.

“Go, destroy the Rainbow Booms!” Arkham ordered.

The Demon-Dazzlings roars screeching and flew into the air heading to the Rainbooms, the girls did their best to hold them off with their own magic music blasts like rainbow-colored lightning bolts, sparkling star blasts, but they weren’t enough as the demon sirens unleash their demonic sonic scream knocking the Rainbooms down and Twilight dropping the microphone as it rolls near to Sunset’s feet.

“Sunset!” Flash gasped.

“Come on.” Nevan grabbed Flash and she teleports them right to the group with her lightning travel.

“Whoa, how’d you get here and who’s the demonic hottie?” Pinkie asked.

“No time for questions, Pinkie. Sunset Shimmer, we need you!” Twilight said.

Sunset hesitated not sure Twilight said they need her, she felt scared that she might screw everything up until she felt a hand on her shoulder turning to see its Flash.

“You got this, Sunset.” Flash believed.

Sunset smiles feeling the encouragement from him and nodded.

“You’ll need my help to save my daughters.” Nevan said.

“How?” Flash asked.

The answer came when Nevan shines into a bright light for a moment and transform into a purple, one neck guitar with many electric strings and some skeletal-looking features.

“Whoa!” Flash, Sunset, and the Rainbooms shocked, even Spike and Vinyl are shock too.

“Combine the demon power with the girls’ magic to overcome the power that is consuming my girls. Please.” Nevan begged.

“Okay, ready?” Flash asked Sunset.

“Ready.” Sunser nodded as she threw her coat off and Vinyl starts playing a beat rhyme as Flash shred the demon guitar to that same rhyme too.

Flash glows red of his demonic energy spreading it to the whole group giving them new power mixing in with the Magic of Friendship.

“Destroy them now!” Arkham ordered in rage

The Demonic-Dazzlings charge at the girls, but Flash blow them back with his single guitar shred.

Then another amazing thing happen: Sunset has transform into her pony girl form making herself the official member of the Rainbooms and part of the Magic of Friendship, then everyone starts floating in the air together.

Arkham watches the sky to his horror seeing a giant rainbow ball swirling around and out came a giant Alicorn with two feather wings on the left and bat wings on the right.

The Alicorn fires a demonic rainbow beam at the demon sirens engulfing them into the light shattering their form and destroying their pendants as well. Thus, ending the Battle of the Band.

(Music End)

Flash and the girls along with Spike ran to the stage to quickly check on the Dazzlings, the half-devil boy quickly took out his guns as he lets go of Nevan letting her transform back.

“Time to sing your last note.” Flash punned.

“Don’t think this is over!” Arkham angered, disappearing in a dark-red mist in an instant before Flash can shot him.

“Girls, are you alright?” Nevan asked.

The Dazzlings groan starting to wake up.

“Waiter, there’s demon music in my soup.” Sonata dizzied.

“What… what happened?” Adagio asked.

“Oh, you girls were transformed into demons by Arkham controlling you into killing us and all.” Flash explained.

“Son of a bitch! I’m going to kill him!” Aria declared, getting up but felt exhausted a bit and Nevan helps her.

“Easy, my child, there will be time on getting revenge later.” Nevan said.

“Guess we won’t be needing these anymore.” Adagio sighed, looking at their shattered pendants.

“Without them, you three are now just harmless teenage girls.” Twilight pointed out.

“Yeah, no shit, Sherlock.” Aria rolled her eyes, then Nevan push her a little forward.

“I mean-thank you for saving us.” Aria thanked.

“Sorry we didn’t listen to you about before, mom.” Sonata apologized.

“It’s okay, I should’ve done something about this sooner, but now we don’t have to worry about struggling anymore.” Nevan pulled her adopted daughters closer for a family embrace which earn some “Aw” from the crowd and the Rainbooms.

“So, what now?” Sonata asked.

“I got plenty of spaces at my place, you all can live there as long as you want. If that’s okay with Twilight.” Flash offered.

“I believe that would be for the best, consider they were also victims as well.” Twilight nodded.

“Thank you, we promise you to repay this kindness.” Adagio smiled.

“And Twilight is going back to Equestria soon. The Rainbooms could really use someone to help Fluttershy on backup vocals.” Rainbow pointed out, looking at Sunset hoping she will join.

Sunset decided to show her answer by playing a guitar awesome impressing the other that they are shock.

“I also play guitar.” Sunset said.

“We’ll see.” Rainbow Dash said.

“It was also cool that you turned into that electric guitar in the big finale.” Pinkie mentioned.

“Wait, you can what?” The Dazzlings shocked and Nevan laughs.

KO a new chapter is done and hope you all enjoy it!

The Battle of the Band is finally over, the Dazzlings have been defeated and free from Arkham’s control as they were forced to become demon sirens doing his biding, and Flash has gotten his hand on his first Devil Arm Nevan as I’m sure you’re all surprise of her transforming ability.

Next chapter is going to be something some of you have been waiting for.

KO comment, favorite, click the thumb up button, and follow through of how this story will go!