Things were going so well during the finale of Rara's Guitar Hero tournament, until the Rainbooms' old enemies, the Dazzlings have returned to seek revenge on them once and for all. The girls didn't expect the Neighon Warriors to be behind the repair of the gemstones that once gave the Dazzlings their true voices. Just as the Rainbooms were about to defeat them for the second time, their friend, Starlight Glimmer, wasn't having it either. Her band, in front of the entire world, now faces the three Equestrian evils in order to protect the Rainbooms and everyone else inside the theater. It was four against three, but it seemed pretty even right now.
"I will beat you like a Cherokee drum!" Cheese admonished.
"Is that so, handsome?" as Sonata banged away on her drums. "Two can play at this game!"
"There's three of us, moron!" Adagio echoed. "Eyes on the big screen!"
"You will not win!" Starlight retaliated. "I got sick chops you girls can never hope to play!"
"Hey, doesn't that sound like a lyric from one of my songs?" Rainbow randomly selected. She got a massive pinch from Applejack. "Ouch!"
"No time for jokes, sugarcube! This is serious, y'all!"
"We gotta stop the Dazzlings again before they unleash their musical, evil magic to the entire world!" Princess Twilight begged.
"I think we can let Starlight handle that!" Sunset suggested. "The Dazzlings lost last time and got booed offstage, so another crushing defeat will give them a lot of humiliation!"
"I'm not sure if this is a good or absurd idea." Sci-Twi said.
"Are you crazy, Sunset?" Pinkie's mouth was gaping widely. "Starlight and her friends don't even have magic like us."
"Just trust me on this, girls!" Sunset heartened. "Come on A.J., back me up here!" The country girl gave her a weird look.
"...I hate to admit it, but I'm with Sunset on this one. She did nothing wrong, but I'm quite concerned about where this is going. Gals, flip on your magical geodes in case the Dazzlings pull off something suspicious!"
"I was about to say the same thing!" Sunset replied. "Good thinking, A.J.!"
"Yeah, good idea, pal!" Rainbow thanked.
"Aww shucks, thank you!" as A.J. took off her hat. "But seriously, keep them eyes peeled, y'all. Rara!"
Her pop star friend then nervously trembled and almost tripped until she met up with Applejack. "Y-yes?"
She put a hand on her shoulder for comfort.
"Everything's going to be alright, Rara!" Fluttershy calmed.
"What?" James Hetfield turned his head to the Rainbooms. "Did you just see what those three ladies did to our security detail? They're monsters!"
"A.J., do you think this'll be a good time for you and your friends to transform, or pony up, as you've showed me before?" Rara wondered.
"I think we all want to, Rara, but Starlight Glimmer might have something up her sleeve. If she fails, we'll be on standby. Alright?"
"Okay..." Her friend replied.
"Let's see how you can handle these lead licks, Adagio!" Starlight challenged her. She got up closer to her and both leaders were at the center of the stage.
"Throw everything you've got, Starlight Glimmer! Once we breeze through your band, the Rainbooms will be our concern!"
"Huh, is that so?" Suri objected. "Activate Star Power!"
"We can do that too, you know!" as Sonata struck the button to activate Star Power.
With her band dueling out the Dazzlings, Babs Seed met up with the Cutie Mark Crusaders in Rara's dressing room, which was left unlocked by the demons. Everything was still going live around the city and world as the four kids watched both in horror and suspense. They sat down on the sofa and looked at each other.
"Our sisters better handle these Dazzlings again!" Apple Bloom cried. "I ain't gonna let Applejack be beat by some filthy maniacs!"
"Oh, Rarity better act fast!" Sweetie Belle worked herself up. "What're we going to do?"
"Can we call Gabby to try and get us out of here?" Scootaloo asked. "She's almost as fast as Rainbow Dash, so there shouldn't be a problem trying to bail out."
"Sorry y'all, but the Dazzlings locked us all in this place with their crazy magic." Babs noted. "The only way we're leaving is if your sisters' band kicks them to the curb!"
"Umm, I thought you said Starlight Glimmer was taking care of the Dazzlings." Apple Bloom said.
"She's barely holding them out there with Suri and Cheese, and I got a bad feeling that something strange is 'bout to happen in the end!" Babs countered.
"Like what, Babs?" Sweetie grew curious.
"I don't know, but it's definitely something. We gotta warn the Rainbooms right this instant, maybe ask them to do their magical transformations like you gals keep telling me about." Babs put on a grin of hope, while her three friends still look worried and not joyful in the slightest bit.
"No." Apple Bloom intervened. "I think I'm starting to have more faith like my sister, Applejack, and I say that your friend, Starlight, has got this. There ain't no way she's losin' to these wranglers!"
"What makes you say that?" Scootaloo minded.
"It's the honest truth." A.J.'s sister came to terms. "Just trust Starlight. After all Babs, she picked you to be a part of her band, am I right?"
"She did."
The Cutie Mark Crusaders all sat together and watched the battle between the other Enforcers and Dazzlings, which was still going on. On stage, Sunset Shimmer and all of her friends kept on cheering for Starlight, while all members of the audience cowered in fear and held on to each other for safety. For Starlight, this was considered to be the second round of the semifinals.
"Is that the best you girls got?" The Enforcers' guitarist roused. "You three actually suck!"
"How is she making this so easy and awesome at the same time?" Rainbow hinted at her friends.
"Meh!" They all shrugged. "Go Starlight!"
"Ugh, you girls are supposed to be helping me back there!" Adagio commanded.
"We're trying so hard!" as Aria strained with the bass guitar. "Maybe you should pick it up, Sonata!"
"Don't tell me what to do!" She gave lip.
"Oh, what's this?" as Rara peeked at the big screen. "The Enforcers are actually winning against these Dazzlings so far with nine million points!"
"Everyone, move up and give them your loudest and heaviest screams!" James directed at the audience. "Let's bring Manehattan to glory, shall we?"
"GO, GO, GO!" The crowd blared. "Let's go, Enforcers, let's go!"
"Uh-oh, looks like you three are down for the count!" Cheese Sandwich grinned.
With everyone's support, including the Rainbooms', the Enforcers looked more fierce than before as they were about blow the Dazzlings out of the water in these last few moments of the current song. Adagio grumbled, "We're not ready to lose! Why don't you try this on for size? C'mon girls!"
"Whoa oh oh!" All three Dazzlings harmonized to summon their true Siren forms again. This time, they've created melodic notes that took control of the entire game. "MWAHAHAHA!!!" Their band chart was now glowing red.
"Hey, you girls can't just cheat by boosting your score like that!" Sunset argued.
"Enough playing by the rules!" said a glowing red Adagio.
"What evil person would follow the rules anyway?" added Aria.
"Not us!" followed Sonata.
"You still won't win, Dazzlings!" Starlight fought back. "You may not have realized it, but your score is SLOWLY increasing and is nowhere near ours!"
"Hehe, take a look!" Suri chortled.
"MORE POWER!" Adagio yelled. "Without magic, you can't do anything!"
"Say goodbye to your high score, Enforcers!" Aria commented. "We can change our Star Power into...Leech Power!"
"EAT THIS!" as Sonata struck a cymbal button.
With the Dazzlings' dark magic, things took a turn for Starlight Glimmer and her band as their score started to decrease and add on to the Dazzlings' score. Leech Power was taking tens of thousands of points away from the Enforcers, causing the panicking to return in the room.
"Sunset, we have to do this now!" Sci-Twi leaned over to her friend.
"Fine." She replied reluctantly. "Hold hands, everyone!"
"Right!" The other eight united.
"Here we go again..." as Sunset closed her eyes. After flashing lights reflected off every surface of the room, she and her friends have turned into Crystal Guardians again, thanks to their magical geodes. "Come on, girls!"
"Wait, look at the princess!" Fluttershy paused.
"She looks...FABULOUS!" Rarity gushed.
"Wow, you look almost exactly like me!" Sci-Twi revealed to Princess Twilight. "The only thing you're missing is my pair of goggles."
"Wow!" The rest of the girls came in.
"Thank you!" Princess Twilight ushered in. "My vision is perfectly fine, so I don't need goggles."
"So, what're we waiting for?" Rainbow Dash hastened. "Let's kick the Dazzlings' butts once again!"
"No need, girls!" Starlight interrupted. "We won!"
"WHAT?" Everyone, including the Dazzlings, broke off.
"Who's dazzling now, hehe?" Suri bantered. "Sorry..."
"I was going to make that joke!" Cheese clouded up.
"Unbelievable." Rara picked up the microphone again. "The Enforcers...actually won!"
"They dropped from nine million points, only to have recovered themselves back to that exact spot!" James announced. "I've never seen that happen before!"
"YEAH!" The crowd and world incited. "Woohoo!"
"Sunset, over there!" Pinkie pointed to the Dazzlings. "Their red gemstones have a little crack in them!"
"You're right, Pinkie." as she observed. "But, I'm pretty sure they're too embarrassed by another defeat to even fight back!"
"Hahaha!" The other Rainbooms laughed.
"You made a deal, Adagio." as Starlight walked over to the rival leader, who was kneeling down on the ground. "That being said, I want you and your buddies to get out of here! Don't come back, either!"
"L-let's go, Adagio!" Aria simmered down.
"Adagio?" Sonata went to check her out.
"We lost... WE LOST??? NO, I REFUSE TO ACCEPT THAT!!!" Her red aura came back and she started to release an even darker and bigger version of her Siren form.
"This ain't good!" as Applejack started to feel the ground shake.
"AHHHH!!!" Everyone else freaked out.
"Get down on the ground!" Rara instructed.
"Hold up, what?" Rainbow stopped in her tracks, trying to escape. "Why do I have my real guitar?"
"Mine came out of nowhere as well!" Sunset exclaimed at the top of her voice.
"All of our instruments poofed up, too!" Pinkie shouted.
"Two microphones?" Princess Twilight inspected.
"We're going to need all the musical firepower we've got, ladies!" Rarity said.
"Sonata, let's run!" Aria rushed her.
"No kidding!" Both of them went out the back door, which was the only exit left.
"They were useless to me, anyway!" Adagio passed off. "You're going down with me, Rainbooms!"
"Not today!" Sci-Twi stepped up. "You've lost to my best friends once, so you're going to lose again!"
"Is that so, Twilight Sparkle?" Adagio bet. "They may have handled three different beings from Equestria, but can they handle three of me?" Suddenly, she sang to summon two other clones of herself.
"Enough talking!" Sunset concluded. "You want a rematch? Then we'll give you one, alright! Huddle up, girls!"
"1, 2, 3, Rainbooms Forever!" They all chanted.
"Instruments up, y'all!" A.J. reminded.
"Aww, how cute!" Adagio remarked. "But just as Sunset said, let's stop talking and fight once again!"
"Bring it on!" The Rainbooms stated.
Inside the game, both bands had their note charts powered up, with the Rainbooms using their magic to add the remaining instruments to the game, while the three Adagios' charts glowed dark red, so they all had tricks up their sleeves.
"Be careful, Rainbooms!" The Enforcers encouraged.
"Stay safe, baby!" Timber Spruce hoped.
"Do it, sis!" Apple Bloom cried.
"You can do it, Rarity!" Sweetie Belle praised.
"Do your awesome thing, Rainbow Dash!" Scootaloo pumped herself up.