My name is Sombra Lucent. I am a resident of the Crystal Kingdom, hailing from the upper class sector. I am making this journal entry to archive my recent magical studies of artifacts and our history.
For as long as our people can remember, our kingdom has been the heart of Equestria. We keep balance and harmony across the land, and take great pride in our duty. Our love is their love, say they say.
But I want to find the source of all of this. I want to discover why the Crystal chose us in this otherwise desolate tundra of cold and ice, and what effects it may have on the kingdom itself. All of this exposure to the crystal has given our coats a glorious shine, and we as the shining guardians of Equestria have been aptly named 'Crystal Ponies'. But while our role in this world is strong, we are also quite fragile in mind and in body.
I have left the kingdom, braving the snow and ice to locate answers to our past and the origins of the crystal. I also hope to find some way to improve my magic and perhaps bring new ideas and studies to what I consider an otherwise crumbling society. They need a leader, they need to stop with their dreams of a crystal princess because in all this time of waiting and legend, there has never been one present among us. She is just a bed-time story for foals at this point, and I refuse to accept the praise and reliance on something that simply isn't there.

This story is a sequel to Utaan

Rainbow Dash traverses the perils of the Dark Side of the world to reach the Midnight Armory.

Cover art by Dafaddah

For as long as the oldest of them could remember, the Guardians had defended what remains of humanity against the forces lurking in the dark. With gun, blade and the Traveller's Light, the heroes born of Earth put themselves between the monsters from the void and those too weak to fight back. Human, Awoken, Exo; the physical coil of the Guardian had never truly mattered so long as they were willing and capable of defend their homeworld.

Until a Guardian came from the wastes that was neither Human, Awoken or Exo; a Guardian not born of Earth.

(Destiny/FiM Crossover)
(Gore tag for blood and violence)
(Thanks to Noble Cause, BradTheBrony and Metallusionsismagic for prereading!)
(Possible Spoilers in the comments, BEWARE!)

The year is 2557 AD. Four years, seven months and ten days have passed since the activation of Installation 04B and the annihilation of the Flood. While humanity and the Covenant have struck a truce for the time being, and started to rebuild their civilizations, Master Chief Petty Officer Spartan John-117 has been in cryo-sleep, adrift, while his ancillary AI, Cortana, has been trapped in her own thoughts. She had been looking for a reason -- any reason -- to wake the SPARTAN up. Now she had one.

They were crashing.

{Description Edited 4/25/2014: Clarified Installation 04B}
{Edit 05/02/2014: Trimmed character list pending future change}

Idea was given from a story on Reddits r/HFY. Story has also changed course and no longer reflects the singular story, but now many from r/HFY.

They say the being in the Everfree is what you really have to be careful of. With an ax and blood lust, many who entered did not leave. Rumor says the beast can jump to incredible heights, is extremely strong, and is very fast.

The Lumberjack has been living here for ten years and he's made a life for himself deep in the forest, away from the natives. He has territory that the predators wouldn't dream of crossing without permission and he has the resources he needs for a simple life. Too bad everything breaks like paper mache around him.

A changeling gets a very risky and clever idea.
Pretending to be an advanced magic doll left as an anonymous gift in front of Twilight Sparkle's home.
It's so audaciously stupid there is no way it's not going to work.