Twilight and her fellow trainees were brought into the mines alongside soldiers in power armour to train with. Twilight's trainer was Sunset herself. Sunset held back severely during their training, to the point where she was fighting with less power than Twilight could output at full strength. Sunset frowned “You need to control your strikes, so you only hurt others with intention. If you are hurting them by accident, that is a major problem.”

Twilight struggled with this, each day Sunset and Twilight slept in the same cavern. Trained from dusk to till dawn, Sunset also walked around her while she practised unarmed fighting “You’re too stiff. Now you're overcompensating for that. You need to be loose but ready.”

Twilight growled “It’s not easy!”

Sunset raised an eyebrow “Of course it’s not, doesn’t mean that I can’t inform the gaps in your fighting. The Night Sentinels were far harsher in their methodology, they beat it into me until I could do it without sight or sound relying on my body’s instincts alone. Just the feeling of the air moving was enough to fight my enemies.”

Over the ensuing few months Sunset started adding her magic to the fights, teleporting around, striking from multiple angles. Twilight frowned as they sparred “Why didn't you do this during your fight against the demons?”

Sunset frowned “I never thought of it. The Night Sentinel training was rather focused And the ensuing battles gave little time for experimentation, especially when I was already winning fights without difficulty. It took some time to incorporate it into my combat.”

Twilight raised an eyebrow as they continued “Where did the Slayer go?”

Sunset dodged a punch “He lives on Earth, it is his home. He has had many rage filled years of fighting demons. He still keeps in fighting shape but he has been enjoying his peace. We still talk occasionally.”

Sunset asked, “What has changed since I left?”

Twilight explained “Well me and my friend saved Princess Luna using the elements banishing Nightmare Moon’s influence from her, we defeated and reformed Discord. There was a Changeling invasion at Cadence’s wedding, we defeated Sombra in the Crystal Empire and Trixie got her hands on the Alicorn Amulet.”

Sunset frowned “I read about the Alicorn Amulet, I thought about using it to trigger an ascension but after discovering it was culpable of corrupting the user I decided to stay away from it. I’m surprised Celestia let such a thing be out there without investing time in tracking it down.”

Twilight blocked a punch “She probably was busy preparing for Luna’s return.”

Sunset dodged “Why do you think that Nightmare Moon is gone?”

Twilight held up a hand “What do you mean, we blasted her with elements didn’t we?”

Sunset shook her head “Nightmare Moon is not some possessive entity, it is not a ghost, ghoul or other demon. That power was always there, she could always do that. She just permanently took that form during her rampage likely out of anger and sorrow. The only way such a form could generate a personality is if you deny it for long enough.”

Twilight frowned “So Luna and Nightmare Moon are one in the same.”

Sunset nodded “Yes, any Alicorn could develop a dark side that represents the parts of you that you reject being part of you. Celestia probably has one, she has always been repressing herself. Nightmare Moon’s love of theatrics is something that Luna also has, Luna was a patron of the arts based on the books I had read.”

Twilight whined, “Celestia hid those books from me.”

Sunset groaned “Twilight, Celestia hides stuff from everyone. There is not a single pony alive or dead who knows everything about Celestia.”

Twilight blinked “Really?”

Sunset nodded “She has so much history that she hides from everyone. Her romantic partners, her role in major conflicts. Trust me, her not telling you something is nothing new. She keeps secrets for a good reason, I have lived a long time. Once you have hundreds of years under your belt you keep more secrets.”

Twilight looked at her wings “Will I start doing that?”

Sunset shrugged “Probably, now let’s get back to it.”

As they got back to training, Twilight frowned “What are your plans after this?”

Sunset frowned “Well, I’ll have to find a way to return you home which means I need a vector to get you back home. Once we find that, I’ll be able to get you home. Still I can’t leave until my plans here are finished.”

Twilight nodded as the two continued, preparing for the incoming conflict. Meanwhile in the other cabins, Kelly frowned as she kicked one of the poor trainers into a wall “Why isn’t Twilight training with us?”

John frowned as he sent another hapless trainer into the wall“She is not like us, we are still young. We have a way to go before we grow into the warriors we were meant to be. She is full grown, it means her training is different. Not to mention she needs to learn how to use her unique abilities in combat.”

Sam nodded “Indeed.”

During the following years, Twilight learned how to teleport in combat while Sunset regaled her with tales of the past. She also taught what she knew of dark magic, Sunset had never used any of it but taught her the theories behind dark magic and it’s corruptive influence on the user.

During Twilight’s training, John went on a mission to capture the leader of the United Rebel Front. Sunset did want Twilight to get some field experience but the mission coordinator objected, given the stealth of this mission and how Twilight’s inhuman physical characteristics would draw unnecessary attention. Twilight’s training continued which would lead to facing a far greater threat than some rebels.

Author's Note

I'm hoping this is where this story takes off.