Author's Notes:

So it's safe to say I've thrown an update schedule completely out of the window.

The next chapter or two I intend to be mostly slice of life focused, but I also wanted to talk about the fight scene in this chapter. I've used music for it, but I'm still on the fence as to whether it fits in this story or not. Personally, I think music enhances scenes in a unique way, but there's also the matter of whether it actually fits in the story.
Obviously, the music is completely optional and you don't need to use it, but I have marked a place where you should stop playing it. I'd mostly like to know what you think about using music for fight scenes, as there is at least one more fight scene that I intended to use music in.

Music used:

-Pokémon Sword and Shield: Chairman Rose Battle Theme

"Storm..." Twilight said, standing in the centre of the Golden Oak Library, "You know you don't have to do this, right?"

You had heard that many times. The amount of times Rainbow Dash had tried to talk you out of this, but it still felt like you had to do it. It was technically your fault you were all in this mess, after all.

"Yeah! We could just wait until Null gets here and beat him then!" Rainbow exclaimed, still searching for an alternative.

"Rainbow, if Null gets here then I'll have no magic and Princess Luna might..." you explained, deciding not to finish that last sentence. You knew how much the princesses meant to Twilight, so talking about their potential deaths might have upset her.

The twin princesses were supposed to be immortal, but their were still ways to restrain them to the point that they were essentially dead. Plus, in the dream world, a lot more was possible than there was in reality.

Rainbow Dash looked at the floor in shame, realising that attempting to persuade you otherwise would have been selfish. Allowing Null to proceed would only put Equestria at even greater risk.

"Wake me up if anything goes wrong, ok?" you told everypony.

"How do we know if anything's wrong?" Fluttershy asked, quietly. Thankfully, nopony else had any questions, otherwise you probably wouldn't have heard her.

She actually made a pretty good point. How were they going to know what's wrong?

"Um..." you began, thinking of things that ponies would usually do in the event of a nightmare, "If I start seeming scared, wake me up."

That was the best you could think off, and it wasn't like there was no chance of it happening. Fluttershy seemed to think that it sufficed, and gave you a nod.

"So, um..." Twilight began, nervously, "Are you ready, Storm?"

You took one glance at Rainbow Dash, then a glance at your friends, then turned your eyes to the window. It had suddenly began to rain, lightning crashing down every so often, but it had been sunny not too long ago.
Ontop of that, nopony else seemed to notice the storm outside.

Turning back to Twilight, you answered her question, "Yeah, I'm-"

"Wait!" Rainbow Dash called, interrupting you. Whilst she interrupted you quite a lot, you were never bothered as it was usually for something important. This time was no different.

Not missing a beat, Rainbkw flew up to you and pulled you into a tight mid-air hug. Everypony was watching, with large smiles on their faces, but she didn't care.
And neither did you.

"Make sure you wake up, ok?" she asked, breaking the hug with a smile.

"I promise." you replied, smiling back. You had a feeling you knew what she was going to say next.

"Pinkie promise?" she asked. You called it. You knew that she was going to ask you to Pinkie promise, but you didn't mind. Last time, you had broken your Pinkie promise to Twilight, but you didn't intend to repeat that mistake.

"I Pinkie promise." you said, giving her some sense of relief.

Instinctively, you turned towards Pinkie Pie, who had a huge grin on her face, "Now that you've Pinkie promised, you have to wake up, or I'll put you into a sleep you'll never wake up from!"

Your eyes widened as you stared at her, confused. Did she just threaten your life... cheerfully?

"O...k?" Twilight replied, slowly turning away from Pinkie to face you, "Now are you ready?"

You nodded your head, a determined grin on your face. So long as you didn't give up, you could achieve anything, and this was no different.

Everypony watched, having full confidence that you would awaken with Princess Luna at your side, as Twilight closed her eyes. Her horn began to glow purple, getting brighter and brighter, until...

Darkness...

It seemed that the spell had worked, but as of right now, you weren't dreaming. You were simply stood in a void, once again.

You attempted to get your bearings, but there were no bearings to get. Not until you started hearing sound.

Mysterious sounds were coming from a purple light not too far away, and you had a feeling that was where you were supposed to go.

Somehow, you were able to fly, unlike the last time you had visited this void. Thanks to this, you were able to reach the light in no time at all.
Or at least, you would have if it was getting any closer.

No matter how fast you flew forward, the purple light never seemed to be getting any closer. You were almost considering giving up, until another blinding light consumed your vision.

After a while, your sight returned, and you looked around.

You were still in a void, but there seemed to be a red border surrounding the area around you, as if it's was the perimeter of this dream. Not far from you stood Princess Luna, who had a large purple beam of magic shooting out from her horn. It looked as I felt she was struggling to hold it.

"Luna!" you called, too taken aback by your happiness to see her that you didn't bother to look at where the beam was heading.

Hovering overhead was the same shadowy pony that you had talked to in your dream not so long ago, but this time he looked more real. More... complete.
He was surrounded by a dark purple sphere, which seemed to holding him in place, but he was making efforts to escape.

Using all his might, he was crashing against the sides of the sphere, occasionally attempting to use your drained determination to try shattering it, but Princess Luna's own magic was too powerful.
However, her limit was nearing.

"Luna, can you hear me?" you asked, seeing the struggle that she was undergoing.

"Storm?" Luna asked, opening her eyes to see you, "What are you doing here?"

You were expecting her to ask this, but you didn't feel like you had the time to answer, "I'll explain later, but it looks like you need some help."

Princess Luna looked away from you, going back to putting all of her effort into keeping Null contained, "I think I have it under con-"

Half way through her sentence, the glow around her horn began to fade. She was beginning to reach the limit of which her magic could take her.
Even Alicorn goddesses could still feel fatigue.

"Yeah, it doesn't look that way." you said, not worrying about the slight rudeness of your statement. You were aware that it was no way to talk to royalty, but you were too focused on the sphere around Null, which was slowly beginning to blink in and out of existence.

"Storm, get out of here. I'll handle this, you just need to get ready!" Princess Luna pleaded, but that wasn't a plan you were intending to follow.

"Not happening, princess." you replied, continuing to watch the fading prison that kept Null restricted. Upon noticing the barrier beginning to fade, he gave you a grin.

"Nice of you to join us, Storm! It'll be a lot easier to drain your element if you never wake up from this dream..." he said, sadisticly. You braced your wings for flight; as soon as the sphere's restraints wore off, the fight would begin.

"There's one problem with that..." you began, giving him a determined stare, "I know I'm going to wake up after this."

Null gave you a patronising smirk, sneaking glances at the weakened Princess Luna as if studying for potential threats, "And how would you know that?"

Your wings fanned out as the bubble vanished, releasing him from his temporary prison.

"I Pinkie promised."

https://www.youtube.com/watch?v=ugyONbAGE8E&t=67s

His smirk didn't fade, as if amused by your 'promise'. In the end, it was up to him and you as to who was making it out of this place.

Without a word in response, Null launched at you, a yellow spear manifesting in his hoof. If that was to hit you, it was going to hurt a lot.

Leaping out of the way of his weapon, he turned around and leapt at you once again, this time almost hitting you. You weren't expecting a second attack that soon after, but you had one advantage.

Wings.

Taking flight in order to dodge his attack, you began to prepare your counter. Focusing your energy on the shadow pony before you, you fired a magical yellow beam in his direction.

At first, he seemed worried, but upon realising that he too held a piece of your element, a yellow shield appeared before him, blocking the laser.

It seemed like you were gonna have to try a little harder than that.

Too your surprise, he seemed to have a way of attacking you in the air. Despite the training you had done with Mane 6 a few hours ago, there were still a lot of things you didn't know about your magic.
It seemed like Null was going to teach you a few new tricks.

Your eyes widened as his horn began to glow yellow, firing a barrage of yellow balls of energy at you. They didn't seem too hard to avoid, but then you realised that they were following you.

If you planned on staying in one piece, you were going to have to use your magic for something other than offence. Focusing your magic on your wings, you began to fly at twice your precious speed, easily outrunning the yellow balls of death.

"I see you are trained in the arts of determination..." Null said, his horn still glowing yellow despite there being nothing happening, "But nopony is as experienced as me."

You gave him a confused look, but then you felt your wings starting to feel strange. You were slowing down, and you didn't know why.
If you didn't descend towards the ground fast, then the fall that was soon to come would most likely kill you.

As fast as you could, you descended, suddenly realising what was happening. Null's own determination was cancelling out yours.

"Now you've got no way to escape..." he said, smirking, as he prepared another barrage of attacks. Before you knew it, three more homing balls were launching towards you.

You couldn't escape, but what if you could do something else? If Null could cancel out your magic, then what was stopping you from cancelling out his?

This time focusing on the yellow spheres before you, you could feel the magical forces behind them slowly falling under your control. Moments before they made impact with you, you gained control of them.

"What? How!" Null cried as his own attack was turned against him. His expression changed to one of shock and hopelessness as the homing balls locked onto him, quickly advancing in on his position.
If you were lucky, this could be the end right here.

Unfortunately, luck was not with you, as just like before, a magical yellow shield formed in front of him, protecting him from the blast.
Thankfully, the shield was shattered in the process, sending shards of yellow glass into the air before vanishing completely. You weren't sure of how it worked, but it didn't seem like he would be able to use that again. Not any time soon, at least.

Sensing an opportunity, you fired several rapid blasts of lasers at him. You had never learnt to use this, but it seemed like the most basic form of magic attack.

Much like you expected, Null's large size made him an easy target for the laser blasts, and since he had no method of protecting himself, every last shot hit.

"I've had enough of this!" he roared, his yellow eyes fading completely to black. It was as if every bit of determination he had was focusing on one thing.
Killing you.
And in the process, that determination manifested into something more. At heart, it was still determination, but this magic's only intent was to kill and to harm.

His horn glowing a deep black, he began to charge a large magical blast. You had a strong feeling of what was to come, and chose to prepare for it.

After a few seconds, Null fired a huge black beam of shadow in your direction, vapourising every last thing in its path. In retaliation, you fired out your own magical yellow beam, and both collided in mid-air.

Despite the circumstances, it was honestly the second coolest thing you had ever seen, rivalled only by the spectacle that was the Double Rainboom.
Two forces of good and evil clashing in the air, but only one can win. Who was it going to be.

Just for a moment, it felt like you were winning, but that hope was quickly crushed. The beam of shadow began to overpower your magic, pushing it back further and further. If you didn't do something, pretty soon it would be the end.
It seemed like Null's will to kill you was somehow stronger than your will to succeed.

The black beam of death was progressing, closer and closer, and it was beginning to look like there was nothing you could do. You braced for the moment that it would hit you, vapourising every last remnant of you, but it never came.

Opening your eyes, you were surrounded by a purple bubble. The beam of shadow was still hitting the bubble, but it was not hitting you.
Princess Luna had stood up, her horn glowing purple, and was smiling at you.

"Don't come back for me, ok?" she said. You weren't sure what she meant by that, "Oh, and... Tell my sister I'm sorry."

'Sorry? Sorry for what?' you wondered, looking at her with a confused expression from within your bubble of safety.

Within a blink of an eye, your vision flashed purple, and you were no longer in that bubble. Turning around, you saw Princess Luna stood in your place, taking the full blast of the beam.

Your jaw dropped as you watched the dark beam consume the Alicorn, but she didn't scream. In fact, she didn't make a sound.
Even Null looked surprised by her actions.

He stopped firing the dark beam, and looked in the direction of Luna. She was still there, but was laying on the floor, unmoving.

"Luna..." you whispered, staring at the unmoving Alicorn is disbelief.

Null approached the body, but you were too taken aback by what had just happened to care. He placed a hoof on her horn, "Did I just..."

You could tell whether she was dead or not, but it didn't vapourise her like it should've done. That was meant to kill you and that was it's primary purpose. Perhaps it had had a different effect on her.

"Luna!" you cried, beginning to gallop towards Null at full speed. Her turned around, a surprised expression on his face. You couldn't tell whether he regretted what he had done, but he had won this fight.

Moments before you collided head on into the dark unicorn, your vision was once again blinded by white as you began your return to reality. Luna was the reason for that dream's existence, and without her consciousness present, that dream could no longer exist.

Rubbing your eyes, you vision began to return, and you felt yourself laying on the cold, hard floor of the Golden Oak Library, all of the Mane 6 staring down at you with worried expressions.

"Storm?" Rainbow Dash was the first to ask, as you slowly but surely regained your senses. You groggily got up of the floor, rubbing your eyes with a hoof, "What happened? Are you ok?"

You had to admit, it was nice to see her so concerned about you, "I'm fine... I think..."

Everypony moved to the side in order to give you some space, before Twilight asked you the one question that you didn't want to hear; the one question that you wished didn't need to be asked.

"Where's Luna?" she asked in a concerned tone.

That was a question you didn't want to answer. Instead, you stared down at the ground, your ears drooping. Truthfully, you weren't sure if she was dead, but either way, she was trapped in the dream realm with seemingly no way of escape.

The best answer you could give her was: "She's not dead, but..."

Seeing everyone's mood suddenly drop made you not want to continue your sentence. You didn't want to lose hope, though. If she wasn't dead, then there was surely a way to bring her back to reality.

"And Null?" Rarity asked. You weren't sure of his fate either. Sure, you didn't kill him yourself, but maybe the collapse of your dream did some damage to him?

Looking above your head, you could see your element hovering above you, the dark black shadow still creeping up it like vines.

"He's still alive." you said, staring at your element with worry.

"Well, we have our elements," Twilight said, letting out a sigh, "We'll just have to wait for him to come to us, and then we'll save Princess Luna!"

That seemed like a good idea, but surely you had a day or two to spare before he arrived. Your magic seemed strong enough to hold your own, and with the other elements helping you, surely you would win the fight.

"What do we do while we wait?" Rainbow asked.

Twilight though for a moment, but eventually came to the conclusion that there was nothing else they could do at this moment, "Do whatever you want. Enjoy the few days we have before the battle arrives."

It seemed like she had said that with the hopes of cheering everypony up, but all it seemed to do was bring them down further.
She was right about one thing though.

Now matter how much you prepared for it, and no matter how ready you were for it...

A battle was coming.