Celestia was alone in darkness. The shadows filled every inch of space and suffocated all sound. She couldn't see, she couldn't hear, she couldn't move, she couldn't breathe. Just cold, isolation, and anguish. She felt her subjects crying out to her for help and was powerless. Her sister's voice called to her, pleading to make the pain stop. Once again she had failed, once again she had dumped the fate of the world in the hands of poor, innocent Twilight. Gloom was there, he was always there. Gloom's presence ate away at her consciousness, grasping at her connection to the Sun, trying to siphon power away like a parasite. Celestia curled into a ball and shut it all out, it was the only way to keep from going insane, the only way to keep Gloom from using her. Time ceased to have meaning, had it been an eternity, or merely a few seconds? Suddenly it stopped and Celestia gasped as her head was pulled out of a pool of inky blackness. She was up to her neck in the stuff, still unable to move but at least now she wasn't slowly suffocating. Celestia looked around. Gloom sat in front of her, staring intently.
"You can't resist forever." Gloom's statement was emotionless.
"You're right, but I'm still going to try," Celestia replied. Gloom seemed deep in thought for a moment.
"I am torturing Cadance and Shining Armor as we speak, give in to me and I will allow them to pass out, refuse and the pain will continue."
Celestia was shocked, how could this be true?
"See for yourself." Gloom showed Celestia what was happening in the Crystal Empire through the eyes of his other body. Celestia's hopes were crushed, her plan had been to keep this creature focused on her. As long as Gloom was with her he couldn't stop Twilight or Cadance, but how could she distract something that could be everywhere at once? "You don't," Gloom read her thoughts, "In addition to the avatar I have in the Empire and the one you see before you I have one in Ponyville. I am preparing to overpower your student this minute. Equestria is finished Celestia, stop bottling up your misery and let go. It will only hurt more if you fight. It's hopeless."
"What are you?" Celestia demanded, "Why are you doing this?" The entire time they spoke Gloom never once stopped trying to invade the deepest depths of her being, to get at the magic within.
"A number of reasons. I could say that I hate ponies, that I want revenge for past conflicts I had with your ancestors. I could say I want power, that the negative energies I steal from all of you will make me a god. I could say that I envy ponies, I can't feel true happiness, why should you? These are true, but they are not why I do this." Gloom paused and there was silence.
"Are you going to answer my question?" Celestia asked. Gloom leaned close to her.
"I think I will. Just because you are the first being ever to ask me of my motives. I have been asked what I am before, but never why I am doing this. Besides, it is far easier for you to fight me if you see me as some inequine monster that is pure evil. It might shake your resolve to realize that my reasons make sense." As Gloom spoke he turned his back to Celestia and moved to gaze out the window. "Do you ever question why you teach your ponies the value of friendship, why you tell them to spread it across the land? It makes them happy, you think, it makes their lives better, you think. However, at the back of your mind you know the real reason. It is for their survival. Without fueling their magic with things like harmony, friendship, love," Gloom spat these last 3 words with disgust. As he spoke, a letter suddenly materialized next to Celestia's head, sent via Spike's fire.
"Ponies would never be able to survive against all the monsters and powers that would like nothing more than to dominate them. How many times has friendship saved you from certain doom?" Gloom wasn't looking at her, he didn't see the letter. "Countless, am I right. Ponies need friendship to continue their existence in this world. Hate, fear, misery, deceit, greed, loneliness, these things would destroy them. And then we have me, where do I fit in to all this? Have you ever wondered if other concepts could do what friendship does?" Celestia glanced over the letter, it was a call for help from Twilight. "Of course not, that would be like trying to explain how important air is to a fish. To a fish air means suffocation, air means death, but to a pony air is life. Do you understand? Misery is to me what friendship is to you."
An idea popped into Celestia's head, but she needed to cast a spell. Her horn was covered with hardened black sludge. "I am not a changeling or a siren, it doesn't just grant me power, I need it to live. I need to embrace it, I need to spread it. Friendship, happiness, love, hope, the things you hold so dear would destroy me. So in the end it comes down to who wants to live more, me or you?"
Celestia managed to both listen to Gloom and carry out her idea. Centuries in court listening to speeches by nobles while simultaneously thinking of plans came in handy. She was mortified, here in front of her was a creature that was physically and mentally incapable of being happy. A creature that needed to destroy the lives of others to survive. An absolute antithesis to everything ponykind held dear. It didn't matter though, her ponies came first, this creature needed to lose. She focused her magic against the crust blocking her horn. She needed to keep him talking, keep him from turning around. "What made you this way? What force could have made a creature so opposed to all being?" Gloom responded, he was aware of Celestia's struggles against her restraints but mistook them for the general resistance she gave earlier.
"It's a long story, but none of the forces that shaped me gave me a choice in the matter. I didn't start this way, I was originally much simpler. I once depended solely on hatred, a single emotion among many within misery itself. I didn't understand what it was then, only that I needed it. I was later granted complexity and understanding, against my will." Celestia poured what was left of her strength into her horn. She just needed a little magic, a spark. Finally she got it, a tiny crack formed in the crust and her spell got through. A wisp of magic hit the letter and sent it off to somepony who was in a position to help. The spell was so small and weak that Gloom didn't even feel it act. He never knew the letter was there and gone. Gloom turned around and moved to stand in front of Celestia. "Ah, trying to break your restraints again? What a pointless waste of magic, although I'm impressed you cracked them. Did you really think I'd talk long enough for you to break free? I'm insulted." Gloom waved his claw and the black crust on Celestia's horn repaired itself then grew twice as thick. Celestia meanwhile was busy repressing the memory of the letter so Gloom wouldn't find it if he chose to look into her mind.
"Now, where were we?" Gloom stared menacingly into Celestia's eyes.
"You were telling me about yourself, but I've heard enough to understand. You have mutated and changed but I know what you are."
Gloom showed all his teeth and the room got even colder. "And what's that?"
"You're the last windigo."
Gloom's eyes glowed bright blue.