Arcanum Sombran

Umber ducked out of the rain, tugging his hood away--taking a moment to free his horn from the sopping-wet, tangled cloth. It was a foul day in Canterlot; the pegasi had been running behind schedule, and their priorities were focused in Ponyville and the surrounding farmland anyway. Every day it rains in Canterlot, he reminded himself, was a day for which rain was necessary.

It did little to lift his spirits.

"Good afternoon, miss Trance."

"Good morning, mister Smoke."

"Is it morning? I couldn't tell. Damned cloud cover."

"Every day it rains in Canterlot is a day for which rain is necessary, mister Smoke."

"Don't I know it," he harrumphed, as he walked upstairs to his office. He had been working for the Canterlot Institute of Magic for years now, mostly providing an extra horn for other ponies' research projects while he awaited approval for his own. Today, however, his project was approved. As he slipped into the 'cozy', 'quaint' little excuse for an office, he reached under his desk and withdrew a musty, ill-used tome, blowing the dust off the cover:

ACANUM SOMBRAN,
or
A GUIDE TO THE ART OF SHADOW MAGICKS

Beneath the title was the hoof-written signature of one Sombra, who later became the infamous king of the Crystal Empire.

"I shall understand you," Umber muttered to himself, "and you shall be no threat to me."

The basics of Shadow Magic, or Sombran Magic, were well known by the time Umber picked up this book. Everypony knew the signs: Sombran mages were quick to anger, had glowing eyes, and were often obsessed with strength above all else. They appear physically frail, and it is often claimed that the Sombran magics consume the body as well as the soul. It has been observed--most recently by Twilight Sparkle herself--that Sombran magic is easier to cast when one is frustrated or angry.

This is merely the tip of the iceberg, the sliver of a crescent moon peeking out, leaving all of the nightmarish monsters hidden in the black. There are so many more things left unknown--the extent of a Sombran mage's control over others, the ways in which a Sombran mage gains power, whether the glowing eyes will only appear after casting or are a permanent symptom...

Umber's research project is dangerous. It is dangerous by virtue of a simple fact: He is going to learn as much Sombran magic as he can, in order to understand exactly what makes it tick.

Two weeks prior.

"...Umber," the Princess said. Umber could never quite get used to the way Celestia always referred to ponies by their first name. It was unnerving enough to be called before the Princess for this anyway; while he had expected his project to face a fair amount of friction, he had not expected it to go all the way to the rulers of Equestria.

"Umber, my little pony, I hope you understand why I hesitate to approve this."

"Why we both hesitate," Luna added. "Shadow magic is no mere toy to trifle with. Myself and my dear sister have used it before--"

What? The Princesses, using forbidden magic?

"--but only in dire circumstances, and we are only able to control it because of the bonds of friendship--"

"The friendships that keep us happy and healthy," Celestia concludes. "Umber, we are able to use Sombran magic safely because of the magic of friendship. Twilight is able to use Sombran magic safely because she is the Princess of friendship. And you..."

She sighs. "Umber, how often do you spend time with other ponies? Not at work."

Umber closes his mouth, frowning. If he's not allowed to count time spent at work, then the number drops to...zero.

"...Princesses...do you not understand?" He glances from one to the other, as they in turn glance between themselves. "It is because I have no friends that I am able to study this magic. With all due respect, neither you nor Twilight can truly delve into Sombran magic, because you are anchored by the relationships you have--and that anchor prevents you from reaching the depths that Sombra reached."

There is a pause. Celestia and Luna look to each other.

"We must convene," Celestia says softly.

"Dear sister, you cannot possibly be considering--"

"We must convene," Celestia says, a little louder this time. "Umber, you may go. We will send a letter when we reach a decision."

Two weeks later, the letter arrived in Umber's personal mailbox. Not his inbox, at his desk in the Canterlot Institute of Magic, but at his home. It is, perhaps, a sign from the Princesses: We will allow this, and we will know if you step out of line.