The Everfree Forest is a place most would avoid. While the monsters are normally kept at bay by the Alicorn Guard, inside the forest they roam free, thirsty for blood. Most normal ponies would perish within minutes. Then again, Twilight and Cadance weren't normal ponies. They were alicorns.
Ponies had one in a million chance to be born alicorns, and blood alicorn sisters (like Cadance and Twilight) were even rarer. There had been around ten pairs of sisters in the whole of Equestrian history, and all of them had gained fame for their heroic deeds. All alicorns were bound to protect Equestria, and their cutie marks always had something to do with the well-being of the ponies. But to earn them, they had to undergo certain trials at the hoof of the Celestial Sisters.
The first Celestial Sister was Solar Flare, said to be the very incarnation of the sun. With a red coat and a flowing mane of fire, she appeared as almighty and powerful.
The second Celestial Sister was Nightmare Moon, said to have been born from the moon itself. Her black coat and her galaxy-like flowing mane matched her mysterious and towering attitude.
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Legends tell that, long ago, unicorns used to raise the sun and the moon. But then, a war started between the griffons and the ponies. The unicorns, blinded by the chance to defeat one of their most prominent enemies, restrained themselves from raising the sun, causing not only pain and cold to their enemies, but also to their own kin. The pegasi, enraged by this, stopped controlling the clouds and the weather. The earth ponies no longer shared what little they had left of their crops, and so on. It continued that way, until one fateful day the moon left the sky and the sun took its place. The center of the city was filled by surprised pegasi, confused earth ponies, and enraged unicorns.
Suddenly, there was a flash of light. When it finished, two mares stood in the middle of the crowd. But they weren't normal mares. The first one had a bight red coat and a mane made from blazing fire, flowing without the need of wind. The second one had a deep black coat, but her flowing mane represented a galaxy instead of fire. Both of them had horns and wings.
King Emerald of the unicorns steped up and faced them. "What madness is this?! How dare you raise the sun and moon?! Who are you to stand up to us, the Royal Family?!"
The first pony looked at him with dragon-like purple eyes. "My name is Solar Flare. I am the incarnation of the shining sun."
The second pony had dragon eyes too, but they were teal in colour. "My name is Nightamare Moon. I am the daughter of the gleaming moon."
"We are inmortal, and we have always existed. We have protected you ponies for milennias." Solar Flare spoke.
"We have seen how the pride of the unicorns, the rage of the pegasi and the distrust of the earth ponies have almost lead you to extinction." Nightmare Moon added.
"We have decided to raise the sun and the moon on our own."
"You unicorns have been relieved of this task. Instead, your magic shall protect the kingdom and make it a safe place. The pegasi and earth ponies won't leave the unicorns behind, they will continue being one nation.
The non-unicorns in the crowd shifted unconfortably.
"But that is not all." Solar Flare declared.
"We shall give you another protection." Nightmare Moon declared.
They moved their heads close so that their horns were touching, at the same time the latters lit up with magic and they spoke. "A miracle shall happen, and in normal families, winged unicorns shall be born. They will live for the protection of Equestria, their lifetimes lasting a thousand years. But should their hearts no longer be pure, they shall become either one of the three races, and shall lose both their destiny and their powers."
A powerful wave of magic enveloped those present, and all of Equestria.
"Their talents shall not be like the rest. They will have to pass three tests, placed by our hooves, in order to gain them."
A bright light shone from the two.
"And when they need us, we shall be in the forest that will forever be free."
When the light dissipated, they had disappeared.
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"Um, Twi? You there?" Cadance waved a hoof in front of her sister's eyes.
"Uh? Sorry, I was thinking." Twilight said, struggling to get back to reality.
A smile formed in the face of the pink alicorn. "Let me guess. Are you trying to remember the legend so that we'll get some sort of advantage?"
"How did you guess?"
"Well," Cadance started, bringing a hoof to her chin." Firstly, I'm your sister, so I know very well. SEcondly, I know you always think of some solution from the books. Thirdly..."
"I get the point, thank you very much." Twilight blushed, much to the amusement of her companion.
As they talked, they approached what once was a castle, but had been reduced to ruins. According to legend, the entrance to the Celestial Sisters' world was located there. When they were ready, Alicorns could enter them and gain their cutei marks. Cadance could have taken the trial much sooner, but she had decided to wait until her sister was ready, in order to accompany her. Twilight couldn't thank her enough.
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It took a furious two-hours search, but they found two mirrors, one bright red, and one deep black. The sisters looked at each other and advanced towards the mirrors.
Twilight was te first to make a move. She touched the dark mirror, and her hoof slid trough it like it was water. She retreated her hoof and looked at her sister. She was surprised to find that Cadance had done the same thing, but with the red mirror. They looked at each other.
"Ready?" Cadance asked.
"How can you be ready for something like this?" Twilight seemed scared.
A soft chuckle escaped the pink alicorn's lips."When I say three, we enter at the same time, okay?" At Twilight's nod, she turned her head to the mirror. "One, two..."
"Three!"
Both sisters entered their respective mirrors at the same time.