Image imported from derpibooru 
Alt Link (Warning: May link to something unrelated) 
Original Description:
 
Flurry Heart, Pumpkin Cake, Pound Cake, Misty Trail and Dusk Fall are at the Crystal Palace library, looking through the books. Flurry, Pounds, and Misty are in the air flying to different shelves, while Pumpkin is hovering books toward her with her magic and Dusk is searching from the books on the bottom shelves. Misty flies a book over to Flurry.

MISTY: Is this it?

Flurry shakes her head.

FLURRY: Keep looking!

Misty rolls her eyes but flies off to do as she says.

PUMPKIN: There are a lot of books here…Are you sure we need this one, Flurry?

FLURRY: Well…no, but we have to at least stay here until Spike sends word.

MISTY: Who’s Spike?

FLURRY: My uncle, but I usually just call him “Spike”.

MISTY: Princess Twilight had another brother?

DUSK: Maybe he’s more of a distant relative.

MISTY: Or maybe she had a–

POUNDS: The Royal Dragon.

MISTY and DUSK: Ohhhh.

FLURRY (amused): That’s what you call him? You know he’s the Friendship Ambassador, right?

DUSK: What in Celestia’s name is a Friendship Ambassador?

(Flurry opens her mouth to speak, but Dusk interrupts her.)

No, don’t answer. I just wanted that to be said.

PUMPKIN (holding a book with her magic): Flurry, is this it?

Flurry flies over to her and takes the book with her magic. She squeaks in delight.

FLURRY: Yes!

(She coughs, lowering her voice.)

Everyone gather around. This is the tale of Maredusa.

As she reads from the book, the story takes place in front of her (in a different, more storybook-like style.) None of the ponies actually see this happening.

FLURRY: “Once upon a time–over a thousand years ago–there lived a beautiful, powerful unicorn named Maredusa.

“Kind, generous, and exceptionally talented in her magic, she would use her skills to restore the health of others; curing whatever ailments they came to her with. She was loved and adored throughout her village, and word soon spread of the mystical unicorn with magic so strong, she could almost perform miracles. Ponies started to come to her with their requests from far and wide, but she became worn out from constantly draining her power, and began to notice her magic fading as she grew weaker.

“In order to keep up with her new demands, she sought to transform herself into an even more powerful being with magic strong enough to cure every and any pony that came to her. She knew the strongest pony would have to be an Alicorn, but no matter how hard she tried, she couldn’t successfully perform the spell to turn herself into one. As more sick ponies lined up at her doorstep, she grew desperate, and turned to dark magic. A forbidden spell to gain power amplified her magic and gave her wings, but turned her heart venomous and transformed her mane into a bed of snakes. Instead of wanting to cure ailments, she now sought to cause them, and traversed the land undoing all the good she had done.

“Many famous sorcerers around the world tried to defeat her, but she was too powerful for even the most exceptional of them. Then one day, a brave young unicorn named Flashfire stepped up to face her. Amplified by the magic from a passing comet, Flashfire was able to almost completely revoke Maredusa’s magic, cursing her so the only spell she could cast would be turning beings into stone. Maredusa tried to retaliate and strike Flashfire, but she countered her with her own magic and the spell bounced back; turning Maredusa into stone, where she would remain forever encased in her own dark magic.

“But there are rumors that Maredusa never went away for all that long, and she continues to stalk the land and all its inhabitants, cursing them for forgetting all she ever did for them, gathering power from their misfortune until she’s strong enough to strike again.”

Flurry shuts the book. There’s silence as everyone broods in the story’s ominous ending. Pumpkin finally speaks up.

PUMPKIN: Well…that was dark.

FLURRY (exuberant): I KNOW, RIGHT! My mom totally flipped when Aunt Twi first read it to me.

Flashback. A younger Twilight is holding the book in front of her with her magic, reading to a young filly Flurry sitting at the edge of her bed, surrounded by stuffed toys.

TWILIGHT: “…gathering power from their misfortune until she’s strong enough to…”

(She builds up the sentence, menacingly approaching Flurry.)

STRIKE AGAIN!

Flurry bursts into tears, wailing.

FLURRY: WAAAHHHHH!

TWILIGHT: Oh no no, Flurry, I didn’t mean to make you–

Princess Cadance enters.

CADANCE: What is going on here?

(She sees the book Twilight is holding.)

Twilight! I told you to stop reading those old mare’s tales to Flurry.

TWILIGHT: But it’s history!

CADANCE: I don’t want to hear it. Go to your room, and think about what you’ve done.

Twilight sulks away, but turns back when she reaches the door.

TWILIGHT: You’re a great mom, by the way.

Cadance glares at her.

TWILIGHT: Okay, bye!

(She zooms off.)

Cut back. Flurry is thinking back on the memory fondly when a sudden puff of green fire appears from mid-air, bringing a scroll with it.

FLURRY: Spike!

(She takes the letter with her magic, reading it over. Her eyes darken.)

He says Maredusa took Canterlot…

Another puff of fire appears, now bringing with it a circular amulet, engraved with the symbols of the sun and the moon. The ponies lunge to avoid it as it crashes to the ground.

PUMPKIN: He can send objects, too?! I thought it was just letters.

FLURRY: When he was younger, yeah, but now he can send pretty much anything.

Pounds stares at the object.

POUNDS: What is this?

Flurry approaches it, lifting it with her magic and bringing it over to her.

FLURRY: This is Celestia’s and Luna’s amulet, Twilight used to use it to raise the sun and the moon before she absorbed the magic within it. Which is actually a funny story…

Flashback. A younger Twilight has the amulet set on the table in front of her. She lights up her horn.

TWILIGHT: Okay, I can do this…

(Her magic shoots forward toward the amulet. Golden and blue magic rises from out of the magenta aura Twilight had sent toward it and engulfs her, turning her eyes white as the magic enters her. She floats in the air for a moment; golden, blue, and magenta magic encircling her, before everything suddenly stops. She hits the floor, groaning, then shakes herself and gets back on her feet. She looks around, confused.)

Did it work–?

(Before she can say anything else, she starts to transform. Her mane grows, sprouting out into a flowing wavy, length, dazzled with sparkles coming from seemingly nowhere. Her legs start to stretch, her muzzle extends and her body widens until she’s a magnificently tall, unmistakable ruler. The magic stops, she crashes onto the ground, groaning.)

What just happened?

Starlight Gimmer enters.

STARLIGHT: Twilight, Sunburst was wondering if you–

(She sees Twilight, who’s shakily getting onto her new legs.)

Wow. We’re going to have to resize your…everything.

RARITY (off-screen): Did somepony say resize?!

Rarity enters, dramatically fainting onto her couch upon the sight of Twilight. The rest of the Mane 6 follow, staring in awe.

PINKIE PIE: Can you help me reach this balloon I got stuck in a tree?

Cut back.

FLURRY: Apparently size comes with Celestia’s magic. I wonder why Spike would send this, though…

(She stares at the amulet, frowning.)

POUNDS: Maybe he’s trying to tell us something.

FLURRY (sarcastically): No, no he wants us to use it as a plate.

(She catches herself, eyes wide.)

Sorry, I don’t know what got into me. I guess dire situations make me cynical.

POUNDS: Naturally.

PUMPKIN: Does anypony else see that over there?

(She’s staring out the window, where a bright, orange glow is lighting up the sky from a few towns over.)

It kinda looks like unicorn magic.

The others scramble over to the window to look.

FLURRY: I’m not sure…it looks like it’s coming from Appleloosa. My Aunt Applejack has a ton of family there.

DUSK: We should go check it out.

(The others turn to stare at her.)

What? I have a hunch.

Cut. The gang arrives at the Appleloosa train station and step out of the car they were in.

MISTY: I had no idea you knew how to drive a train, Dusk.

DUSK: There’s a lot of things you don’t know about me.

Ahead of the group, they see the source of the orange glow. A barrier of magic has been put up around the town of Appleloosa, shielding it from any outsiders.

FLURRY: Whoa…this is some high-level magic. Like magic-I-can’t-do magic.

POUNDS: So there’s a powerful unicorn somewhere in this town?

MISTY: Maybe they can help us!

Flurry nods, lighting up her horn. She blasts a spell toward the orange barrier, which bounces right back at her. She ducks before it can hit her, shrieking.

FLURRY: Really powerful unicorn.

The sound of hoofsteps clatters toward them and a pony appears on the other side of the barrier, his appearance shielded by the orange haze; Ambrose Apple.

AMBROSE: Who goes there?

FLURRY: It’s me, Princess Flurry Heart! And friends! We’re here to ask for your help in taking down Maredusa. Oh! You might not know that yet. See, Maedusa’s this evil snake mare who turns ponies into stone–

Before she can finish speaking, part of the barrier dissolves, revealing Ambrose on the other side.

AMBROSE: It really is you, Princess! I’m Ambrose Apple, it’s an honor to meet you. Come on in, y’all.

Flurry and the others follow in, the barrier closing back behind them.

Here we go first part of the second part! Sorry for the wait, I’ll hopefully have the other one out soon ‘cause I’ve already finished most of it. I decided to depict one of the flashbacks this time and since Cadance and Twilight wouldn’t fit my redesigns at this time period, I used some great vectors for them and just tweaked sizing and added shadows. I also found a way to make a cleaner color gradient finally which I used for parts of filly Flurry’s mane (although you can barely see since she’s so far away in this). I might go back and edit some older flurrys with the new gradient once I finish…so many things.
Also I wanted to draw filly Flurry so bad so here she is! While doing it I realized I inverted her curls in my design…oh well.
ALSO ALSO I’m choosing to ignore that ep where Twilight gets all the princesses’ powers since she doesn’t grow from that…or maybe we can just say truly absorbing Celestia’s magic is only possible when the recipient is confident in her ability to handle it–which Twi wasn’t at the time. Hee hee.