The six mares hurried into the city's square, where Princess Luna stood grimly shouting orders to royal guards, both regular Equestrian and crystal pony. She spotted the Element Bearers and breathed a sigh of relief.
"I am glad to see thee here, even under these circumstances."
Twilight nodded. "Same here. We got here as soon as we could. What's the situation?"
Luna turned in the direction of the castle, which was now covered in spiky black shards and thorny crystalline vines.
"Celestia went on inside the castle to confront Sombra but we're unable to get inside. It appears to be very strong dark magic is keeping us out."
"Twiley!"
Twilight Sparkle jumped at the sound of her brother's voice but galloped at full speed to tackle him in a hug. She knew that he'd been experiencing some difficulty sleeping after dealing with King Sombra the first time and was afraid of how he'd turn out having to meet that monster again.
"I'm so glad to see that you're alright! You and Cadence have to...wait, w-where is Cadence?"
Shining Armor looked away. "She made a deal with King Sombra that if he let me go, then she'd stay with him."
"What?! Why?"
"I don't know," Shining Armor replied through gritted teeth. "But that creature said that he wanted to speak to Cadence privately, something about revenge but not against her or myself. And then Celestia went in after her."
"So what are we waiting for? Let's go teach Sombrero a thing or two!"
"Rainbow, no!"
Despite Twilight's and Luna's objections, Rainbow Dash zoomed towards the castle, nearing the faintly-seen red barrier that encapsulated the structure. The royal guards tried to stop her but were left gob-smacked when she passed right through the forcefield. Exchanging glances, Applejack shrugged and tried tapping her hoof against the intangible wall, finding that it passed through just as Rainbow did. A pegasus guard copied her, except his hooves glanced off the barrier.
Luna kicked at the solid red wall and shook her head.
"It would seem that only the Element Bearers can pass through."
Applejack gulped but quickly took a calm demeanor. "Well, here Ah go."
Passing through the forcefield, she joined Rainbow on the other side, who patted her shoulder comfortingly. One by one, the others quickly entered, leaving only Twilight. Before she could go, Shining Armor held her back.
"Promise me that no matter what happens, you get yourself out of there. Don't try to be a hero."
Looking into Shining's eyes, Twilight nodded. "I promise. And we'll get Cadence out of there."
Taking a deep breath, Twilight leapt through the forcefield, which then glowed brightly with a malevolent dark red. She felt the barrier with a wing and found that she couldn't pass through the other side! King Sombra was banking on them coming and placed this barrier here to keep them in and everypony else out. But why? Surely he knew that with the Elements of Harmony, he couldn't stand a chance, right? Twilight shook her head. Right now, she had a sister-in-law to rescue.
"Come on, girls. Let's go."
The castle's interior was just as foreboding as it was on the outside, a series of dark catacombs covered in scabs of onyx crystals that hummed with dark energy. A sickly-green mist seeped through the air, obscuring their hooves as they cautiously made their way through the vacant castle. Random spouts of purple fire shot through cracks in the floor, keeping the six mares on their tippy-hooves. Jagged spikes littered the floors and ceilings, giving the ponies the impression they'd stepped into the maw of some giant monster. Fitting, considering who they had come to confront.
"Oh my, this place is so s-s-scary. I liked it better before," Fluttershy whimpered.
Rarity stuck by the pegasus, rubbing her withers reassuringly.
"Indeed! His tastes are horrible! Doesn't he know that Gothic post-modern is so last season!" She moaned, earning a small smile from Fluttershy. Of course, she didn't need to know that Rarity was just as scared. As long as the fashionista kept her mind on the interior decorations, she wouldn't require the fainting couch she was so desperately in need of.
Poking at a stalagmite, Pinkie Pie gave the protrusion a firm lick. "Blech! That is definitely not rock candy!" She then lathered a second one in saliva and groaned, "And that's not black licorice hard candy!"
"If you know that it's not candy then why do you keep licking it?!"
Pinkie blinked at Rainbow Dash and crossed her forelegs. "I happen to be very curious."
Twilight, who'd been walking ahead of the group with her horn glowing, sighed and turned to address them.
"This is hardly the time or place to-..." She stopped, her eyes darting around. "G-girls? Applejack? Fluttershy? Where did you go?" She didn't walk that far ahead and she was so sure that she'd taken a left but the entryway wasn't there anymore. "P-Pinkie Pie? Oh no."
The castle vanished, leaving Twilight suspended in darkness.
"Hello? Hello?!" The alicorn's breath came out in little bursts, the feeling of a panic attack coming on as she fought to remain calm. "Can anypony hear me?!"
"I'm so sorry to scare you like this."
Twilight could almost feel her heart stop. Standing only a few feet away was King Sombra himself, alive and in the flesh. And he had the Alicorn Amulet around his neck! Now that he wasn't a disembodied shadow, she could truly observe him for the first time. He looked exactly like he did in the magic crystal Princess Celestia showed her, sans green smoke or cruel rictus. Instead, the shadow-pony appeared unsure of himself, as if he were afraid of something. Twilight quickly banished that thought and aimed her horn at him.
"King Sombra! What did you do with Celestia and Cadence?!"
The stallion sighed, his gaze forlorn. "I wish we didn't have to meet like this, Twilight. Officially, at least."
"That's Princess Twilight Sparkle, to you!" She shouted, confused as to why the Shadow King was speaking to her in such an informal manner...or why he looked so sad.
Sombra shook his head. "Technically, you're half right. The coronation hasn't taken place yet. You know, I was so horrified when I saw your ascension but now I have to say, wings are quite becoming of you."
Twilight's horn aura died out. "You-you saw that?"
She flinched when he stepped closer.
"Yes. I was on my way to see you."
There was a quick flash of red and King Sombra was replaced with a brown earth pony stallion in a blue mailpony's uniform.
"It's like I told you at the Golden Horseshoe. I wasn't planning on courting you but it happened anyway."
Another flash of red and King Sombra reappeared.
"You...you were...it was you?"
Twilight felt sick to her stomach. It all made sense now.
"You replaced Parcel Post and then made him put himself in the hospital. Oh Celestia and you made me...oh no."
She fell to her knees, tears sliding down her face. She felt nauseous, humiliated but most of all, betrayed.
"Why? Was getting me to fall for you a part of your plan?"
Sombra visibly winced at this. "No. I just wanted to spy on you and your friends. But then we spent time together and I came to admire you. Your intellect, your drive...your beauty."
He closed the distance between the two and held Twilight's chin up with his hoof, the mare too stunned to move.
"Parcel Post was a lie, yes, but the stallion you were talking to? That was me. For the first time in a very, very long time, I could be myself. No king, no prince, no umbrum. Just me."
Twilight glanced up and was sucked into a pair of scarlet eyes that reminded her of red glass. She could see pain, fear, even loneliness in those orbs. As much as she didn't want to admit it, Sombra's confession sounded sincere. And then there was the way he was touching her, as if she were an egg he didn't want to drop. He then smiled at her.
"Twilight, as impossible as it is for you to believe...I love you."
"No!" Slapping his hoof away, Twilight scurried away from Sombra, her horn flaring with energy. "It's not true!"
"Twilight..."
"Don't say it! You can't be! Why should I believe anything you say? You're a murderer, a-a cruel tyrant, a-..."
"A monster?" Sombra finished, an edge of sarcastic anger in his voice. Like a wolf on the prowl, he began to encircle Twilight, making the mare feel very tiny. "Yes, I read what the history books say. What Celestia says! Of course, history is written by the victor, isn't it? Tell me something, Twilight, and be honest: don't you find it a bit strange that you've had to deal with figures that Celestia defeated in the past? Nightmare Moon, Discord...me. Now...why is that?"
"I-I don't know!"
Sombra lowered his head so that their noses were almost touching.
"I'll tell you why. It's because Princess Celestia...enjoys having villains to fight. Her ego is so massive, that she has to have foes to battle in order to earn the love of her subjects. She creates villains to defeat so that everypony loves and adores her."
"That's not true!"
"Isn't it?! Why didn't she use the Elements of Harmony to turn Luna back to good instead of banishing her to the moon? Why didn't she lock Discord up or banish him into another dimension instead of turning him to stone? Why didn't she remove my magic and place me in a dungeon somewhere? Can you answer me that?"
It isn't true! It can't be!
Twilight's head dropped, her horn fizzling weakly. "No."
"No. Because she can't live without praise. Now you truly see why she's known as 'Princess of the Day.' Because she wants to shine brighter than the sun."
Twilight raised her head. "Is this the part where you try to convince me to join you?"
Sombra stopped in mid-stride and peered at her sorrowfully.
"No. You're too far indoctrinated. You could be so much more than just Celestia's pet. And that's what hurts worst of all. Your wasted potential."
A sudden heat erupted around Twilight's head before a small fire burned in Sombra's open hoof, revealing her tiara and the Element of Magic.
"My tiara! Give it back!"
Black tendrils shot from the walls and snapped themselves around Twilight's limbs.
"Sombra, give it back!"
"I'm sorry, Twilight. I wished that we'd met in another life," Sombra stated wistfully before he clamped his eyes shut and growled. "You were right about one thing: I am a monster. Just not the one that you think you know."
"What are you going to do?"
Sombra faced away from Twilight, peering down at the tiara in his hooves.
"Make Celestia suffer for taking my child away from me."
Before Twilight could come to grips with that last statement, Sombra vanished in a burst of purple and black flames, leaving her trapped and alone in the void.