Wrath of the Pony Gods

As Blast was training the group on how to tap into their Ki, and more importantly, their Rainbow Power, somepony was watching them from another world. Meanwhile in the Equestria Girls universe, Sunset Shimmer and her friends were watching their pony counterparts train while they were at Sunset's house. Sunset looked down, not noticing her friends were staring at her sadness.

Applejack said, "What's wrong sugarcube?" Worrying about her friend. It wasn't like her to get this sad over something they couldn't do anything about.

Sunset snapped out of her sadness and sighed, "You girls know I'm from that world. I guess I just feel that I should be there, helping them..."

The rest of the group looked at each other and nodded, without Sunset noticing them. Rarity stood up and said, "Well, we'll just have to find a way to get you back!"

Sunset looked up at her friends and said, "W-What?" not fully comprehending what they meant. When it came to her what they were planning, she burst into tears, hugging her friends one by one, "Thank you so much girls! You have no idea what this means to me!"

A few hours later, they were in Principal Celestia's office explaining the situation. The Principal smiled and said, "Very well, I'll help you get back to Equestria." She went through her desk drawers and brought out a silver hand mirror that was encrusted with six jewels that looked like the Elements of Harmony. She handed it to Sunset Shimmer and said, "I have to warn you, once you go... I don't know if you'll be able to return..."

The news hit the girls very hard, at the thought of never seeing Sunset Shimmer again, they started to have second thoughts. But Sunset smiled and said, "That's okay." She looked back at her friends and said, "You've all been great friends to me, in spite of the horrible things I've done. Even if I can't come back, you'll always be my friends, in my heart. That much I know is true."

Her friends smiled and joined in a group hug, all holding back tears. As Sunset Shimmer activated the mirror, it glowed brightly and she disappeared, her friends saying their final good byes as she did, wishing her luck, and hoping to see her again.

Back in Ponyville, everypony was starting to get the hang of Ki control, well, almost everypony. Fluttershy had been too nervous to even attempt using her Ki. Angel tugged at her ear trying to convince her to help her friends. Blast stopped him saying, "Angel, don't get mad at her. It's not in Fluttershy's nature to hurt anypony, even anypony who she knows doesn't deserve a second chance."

Fluttershy smiled at Rainbow Blast saying, "Thank you Blast, you understand me so well." She was about to continue with her thank you before a loud scream pierced her ears.

A familiar voice shouted "Look out below!" before the pony that the voice came from landed right on top of Twilight.

Twilight's world was spinning from whoever had just landed on her. She saw an orange and red tail covering her eyes and said, "Wait... I know that tail... Sunset!?" forcing herself up and Sunset Shimmer off of her. She turned around to see to confirm that it was Sunset Shimmer, and when she saw her she tackled her into a hug.

Rainbow Blast raised an eyebrow asking, "Do you know her Twilight? I've never seen this pony, not even in my timeline."

As Twilight and Sunset got up from their hug, they started explaining how they knew each other. The news came as a shock to Rainbow Blast, but as he calmed down he said, "I suppose if it's possible for me to travel twenty years into the past, interdimensional transportation is possible too."

Twilight was shocked at the young stallion's vocabulary, his mother could barely read anything that wasn't a Daring Do novel, how could he be intelligent enough to understand what interdimensional transportation was? She shook it off after she the stallion caught her staring at him. She looked at Sunset and said, "Not that I'm not happy to see you again, but what are you doing back in Equestria? And more importantly, how did you get back?"

Sunset started explaining, "Me and the girls were watching you train with that dashing stallion-"

She was interrupted by an angry Rainbow Dash saying, "I catch you making goo-goo eyes at my son, I'll knock you upside the head!"

Rainbow Blast blushed deeply yelling at his mother, "M-Mom! Don't treat me like a newborn foal! I'm fifteen years old!" He couldn't believe his mother would embarrass him like that.

He trembled when he saw his mother glaring at him yelling back at him, "That's not too old to go over my knee!"

Sunset gulped and continued, "A-Anyway, I decided that I needed to help you. Principal Celestia gave me a way to come back to Equestria, but... I might not be able to go back to Canterlot High..."

The news hit Twilight hard as she said, "Why would you do something so reckless!?"

Sunset growled lightly and said, "Because friends help friends, you taught me that, remember? You and the girls helped me build a better future for myself, now it's my turn to repay the favor."

Before the two could start arguing, Blast intervened saying, "As long as she's willing to help us against Black, I'll be willing to train her. An ally is an ally, no matter where they come from. Anypony willing to help me and my world is good in my book."

Sunset looked at him smiling, her orange fur hiding her blush. "Thank you Rainbow Blast. I'll be sure to listen to each and every word of your training."

As training continued, Sunset Shimmer included, Fluttershy finally realized that she didn't want to see her friends die, especially Discord, and began to focus her Ki.

As training wrapped up for the day, Sunset looked to Rainbow Blast asking, "I almost forgot to ask, who's this Black you keep mentioning?"

Blast told her, "Twilight Black, or just Black, is a doppelganger of Twilight. She killed the princesses, as well as Discord and her friends. She's immune to magic, that's why I've been training everypony to learn how to control their Ki. I don't know if you'll be able to help as much as you think you will, since you don't have access to Rainbow Power, but that's not important right now. Let's go rest up, if you think today was tough, just wait until tomorrow."

Rainbow Dash and her son flew up towards Cloudsdale, Applejack went back to her farm, Rarity started dusting herself off, and Pinkie bounced off to who knows where. Fluttershy asked meekly, "D-Do you think I should tell Discord about Rainbow Blast?"

Twilight thought about it for a moment before shaking her head, "No, not yet at least. Even if he's reformed, he may still try to do something without thinking about the consequences first. I don't want to see him getting himself hurt, or worse."

Fluttershy nodded and started flying home. Twilight offered to Sunset, "You can stay with me and Spike at our castle while you're here Sunset. It's the least I can do for you."

Sunset smiled and said, "Thanks Twilight, I'll take you up on that offer." and the three of them started heading towards Twilight's castle.

Back at Celestia's castle, she was finally ready to head off to Ponyville with her sister. She still hadn't told Luna why they were going there, or what the emergency she spoke of was, but she knew she had to get to her student before this 'Twilight Black' did.