//------------------------------//
// The beginning 
// Story: Apocalypse Ponies 
// by cielchat 
//------------------------------//

That day was known as the fall of Equestria. It was the beginning of the end, the first blow. And for many, it was the worst day of their lives.
Corruption had been spreading throughout Equestria. It turned kind ponies cruel, sweet ones bitter, loyal ones traitorous. Princess Celestia knew of it well, as it had afflicted her sister Luna terribly in the early days of their reign. It was the Corruption that had been responsible for Luna's envy and discontent turning to hate and malicious intent, causing her transformation into Nightmare Moon. She visited the outbreaks regularly, using her powerful magic to drive it out and restore the ponies that had been Corrupted. Luna often helped, as she was immune to the Corruption.
One day Princess Celestia received news that there was a particularly bad case that had been hushed up. She rushed to cure the ponies that were affected, ignoring the warnings of her sister. However, because of the stage and mutations of the Corruption, it had become strong enough to overcome Princess Celestia’s protective spell, and infect her.

Luna sent for Twilight, who was visiting her parents at Canterlot, worried that Celestia would not be able to fight it off. 
“Have you written a letter to Spike?” Twilight asked. “We may need the Elements of Harmony for this.”
Luna nodded. “It will take them at least a day to arrive, since they must recover the elements from the Tree of Harmony.”
“That’s right,” Twilight muttered, rubbing her chin. “I hope they don’t run into anything in the forest.”
Luna kept silent on the matter, too worried about her sister to feel anxious about the five mortal ponies. “Shall we see Celestia now, Twilight Sparkle?”
“Yes, yes we should,” exclaimed the smaller alicorn, suddenly brought back to the problem on hoof. The two princesses quickly trotted up the long white staircase to Celestia’s room in the east tower.
“Sister,” Luna called out, hesitantly pushing open the door to Celestia’s chambers. “We have brought thy student Twilight Sparkle to help with the ailment. Perhaps thee will guide us now?”
Twilight peered around Luna’s dark shoulder to see her mentor. The sun princess was lying in a crumpled white heap on her bed, shivering. Unbidden, an image of a balled up piece of parchment came to Twilight’s mind.
Celestia raised her head and looked at the pair of them through one dull lilac eye. “Shut the door, Luna,” she croaked, and dropped her head again. Luna did as she was bidden, and the two younger alicorns approached the bed.
“Sister,” Luna said again, “please instruct us on how to heal you. I have only lent you my strength on previous occasions, and I know not the spell.”
“I will show you the spell, Luna, but do not attempt it on me.” Celestia spoke. 
“But-”
“No, Luna. It is too strong right now to be rid of. I am keeping it at bay, but that spell with awaken the Corruption and give it strength.”
“Then how do we help you, Princess Celestia?” Twilight asked, speaking for the first time since entering the room. Celestia looked at the newly minted alicorn and sighed. So young for the responsibility that would soon be placed on her. “You must seclude me into the sun, like I did with Luna. Only then can I defeat it from within.”
“No!” the gasped exclamation came from Luna, who was quivering now. “No, Tia. I will not spend a thousand more years without you. Equestria needs you. Let me try the spell on you, or wait until the elements arrive.”
“Do not make this difficult, Luna!” Celestia struggled to her hoofs, he once flowing mane now limp. “Every second I spend battling the darkness is a second that I could lose the struggle, and not you nor Twilight could stop me then. I must do this, for the sake of Equestria!”
Twilight stepped back, fear and unhappiness battling in her heart as she watched the two immortal princesses argue. She did not want Celestia to leave, and and she desperately wished that she could cure the Corruption, but without her element she felt helpless.
Luna stomped in frustration. “Do you think that if you left me in charge, I could rule like you did? I may be immune to the Corruption, but few know that! Many still believe that I am Nightmare Moon, someone to be feared and hated. They will not accept me as their ruler!”
“No,” Celestia whispered, “but that is why you have Twilight.”
“What?” Luna asked, her eyes widening. Twilight looked from one to the other, bemused.
“She will raise the sun while I am gone, and you will teach her in the ways of being a monarch. Please, Luna. We cannot dally any longer. Already I feel the darkness growing.”
“But I can’t raise the sun!” Twilight blurted. She blushed as both sisters looked at her. “I- I mean, I don’t know how! And I’m not immortal!”
“Luna can teach you how, dear Twilight. You are a princess now. I am sorry to have to give you such a huge responsibility so soon, but I cannot help it. As for immortality, that remains to be seen.
"One more thing, sister," Celestia said. "to be rid of the Corruption, one must burn it. Do you understand?"
Luna nodded, and Twilight gaped as Celestia stepped back. A glow started to surround the three of them. 
“Luna, if you please.”
Luna sighed, and her horn began to glow. “You know I would do anything to take the darkness from you.”
Celestia closed her eyes. “And you know that I would never let you, even if you could.”
Their magic combined, and as Twilight watched, she started to turn transparent, her outline shining a milky white. Inside, where her heart would be, was a pulsating orb of pure light, surrounded by a dark shadow.
Goodbye, Princess Celestia.
Goodbye, Twilight Sparkle. We will meet again.
Twilight met the princess’ eyes, and smiled a sad, slow smile. Celestia smiled back, and looked to Luna.
Then everything went wrong.
From every corner of the room, the window, the land, shadows flew in and attached themselves to Celestia. It seemed that every shred of Corruption had given themselves to try and overcome the sun princess and turn her to their will. She screamed, and Twilight screamed with her, shooting light at the shadows flying in, trying to stop them from adding to the mass that now surrounded Celestia. Luna gritted her teeth and poured more power into her spell, as if to send her sister into the sun before they took her over. A burst of light exploded from Celestia, and Twilight saw stars as her head slammed against the ground. She scrambled to her hooves, skull aching and vision blurry.
Celestia and Luna stood in front of her- but was that Celestia? She seemed different somehow. Twilight blinked, trying to clear her eyes. It was Celestia, but her gentle pastel mane had been replaced by a river of fire, and her eyes were a deep, dark red.

We are Solar Flare, Celestia said, her terrible voice ringing through Twilight’s mind. We are Corruption.