King Sombra

King Sombra is a male unicorn and the main antagonist in the third season's premiere "The Crystal Empire." Princess Celestia tells Twilight Sparkle that he took over the Crystal Empire a thousand years ago, but was banished into the frozen north. Sombra put a curse on the Crystal Empire which made it vanish into thin air. When the Empire returns, so does King Sombra, who attempts to retake it. He is defeated by the Crystal Ponies' use of the Crystal Heart. His dialogue consists of growls, snarling, hissing, menacing laughter, and five lines.

Development and design
The show's story editor, Meghan McCarthy and another staff member have stated that the character's name is Sombra. A tweet by Hasbro's My Little Pony Twitter account spells the name as "Somber". "Sombra" is a Spanish, Portuguese, and Galician word for "shadow", which comes from the Latin umbra. A differently-shaded version of the armor around King Sombra's neck is used for the 2012 Design a My Little Pony Finalists poster, as part of Steel Masquerade's armor. Jim Miller, the show's storyboard supervisor and King Sombra's voice actor, drew inspiration from the vocals of the Mastodon song "Crystal Skull" for his performance as King Sombra. Meghan McCarthy has said that Sombra was inspired by Sauron from Lord of the Rings and is meant to be a dark presence.

Sombra is a dark gray unicorn with a black spiky mane and tail. Unlike regular unicorn horns, which match the pony's coat color, and are straight and segmented, Sombra's horn is curved, smooth, Sharp at the tip and it gradiates from dark gray to red. He has sharp teeth with two visible fangs unlike other ponies, and also has red irises, but most often his otherwise white eyes appear green and have a purple mist emenating from them, which disappears both times he is attacked. He wears silver armor on his legs and neck, a crown with horn-like points on his head, and a red cape that covers his flank. When his flank is shown, he has no visible cutie mark. When he's turned to shadow in Princess Celestia's flashback only his head remains, and when he returns as an amorphous black cloud, only his eyes are visible at first.

Depiction in the series
Princess Celestia describes King Sombra as a unicorn whose heart is "black as night" who took over the Crystal Empire. In a flashback, Sombra looks down gleefully from his palace on a chain-gang of Crystal ponies, when two silhouettes of Princess Celestia and Princess Luna shoot a beam at him that turns him to "shadow" and banishes him to "the ice of the arctic north". Celestia says he was able to put a curse on the empire as he was imprisoned, which caused it to "vanish into thin air". Celestia demonstrates that if the empire is filled with hope and love, then those emotions will be reflected across all of Equestria, but if hatred and fear take over the Crystal Empire, black crystals sprout from the ground. When Celestia creates the black crystals, her horn is engulfed in black mist and her eyes glow green and emanate the purple smoky trail the same way Sombra's eyes do, implying that she may have knowledge of his magic.

Twilight Sparkle and her friends travel to the Crystal Empire to defend it under the order of Princess Celestia. When they arrive in the frozen north of Equestria they meet with Shining Armor on the outskirts of the Crystal Empire. Sombra rises as a cloud of black smoke behind them and pursues them through the snow. Shining Armor confronts Sombra and shoots a beam at him, which Sombra's "head" evades and lets the beam pass through the black cloud. Sombra then charges Shining Armor, and the scene cuts right before they clash. Twilight and her friends pass safely through the barrier and arrive in the Crystal Empire, shortly followed by Shining Armor, whose horn is now encrusted with black crystals which prevent him from using magic. When they meet Princess Cadance, Shining Armor explains that Cadance is using her magic to "spread love and light" to protect the Crystal Empire, and that King Sombra countered Shining Armor's protection spell. Later in the episode, Twilight and her friends interview some Crystal Ponies. One pony who Twilight interviews tells her that she can't seem to remember anything before King Sombra came to power, and flinches while a superimposed image of King Sombra's eyes flashes over her, then she says she doesn't want to remember anything about his rule.

When Cadance's magic starts to fade, Sombra approaches the barrier, but his horn is sheared off as the barrier rises again. It falls to the ground and transforms into a black crystal which embeds itself in the ground and begins spreading to the crystal gates of the Empire.

Twilight performs "a little trick Celestia taught [her]", which gives her the same green glowing eyes and horn engulfed in black mist as Celestia did at the beginning of the story. She turns the throne black with this spell, and slowly makes the throne room look the way it did when King Sombra ruled. She finds a hidden staircase, and at its bottom is "a doorway that leads to your worst fear", created by "King Sombra's dark magic." When Twilight is under the spell, she has the same green eyes as Sombra; Spike wakes her from this state, but then falls into it himself and his eyes change the same way, and Twilight wakes him in turn.

Eventually, Twilight and Spike find the Crystal Heart, but Sombra, able to invade once Cadance is no longer able to perform her spell, traps Twilight in a wall of dark crystals to prevent her from using the heart. Twilight tells Spike to take the Crystal Heart to Cadance. At first Sombra advances as a pillar of black smoke, and he materializes as his unicorn self at the end of it. Right as he's about to take the Crystal Heart from Spike while standing upon a growing, menacing shard of his own crystals, but Cadance, propelled by Shining Armor who threw her at Spike, snatches Spike and the Crystal Heart. With the return of the Crystal Heart, the Crystal Empire is restored to its former glory, and Sombra, much to his horror, is turned into crystal and shattered to pieces in a flash of light, along with his dark crystals. On February 22, 2013, Meghan McCarthy referred to him as being "dead now".

In Games Ponies Play, Sombra is briefly mentioned when Rainbow Dash says the crystal ponies "lost a thousand years to an evil king's curse".

Depiction in comics
The Midtown Comics cover variant of issues #4 and #5 are two halves that when put together feature King Sombra's eyes in the background.

Merchandise
Series 2 of Enterplay's trading cards includes a card featuring King Sombra, #28. Both sides of the card list his name with a trademark symbol, and the back of the card includes the description "After being turned to shadow and banished to the frozen north for 1,000 years, this black-hearted unicorn is back for revenge! The mere mention of King Sombra's name strikes fear into the hearts of ponies all across the Crystal Empire, and it's easy to see why! Sombra recently returned, only to be defeated again by Princess Cadance and the Power of the Crystal Heart. Some say that his horn survived his defeat, but only time will tell if he will ever return."

Promotional material
King Sombra first appeared on Hasbro's Pony Wedding microsite, which has been accessible since July 2012, before any information about the character was released publicly. The quiz does not refer to him by name. In the microsite's Wedding Quiz section, the quiz "Your dream wedding location!" includes the question "Who should be the MC?", with Sombra as the choice that steers the quiz's result to the Crystal Empire.

Writer M.A. Larson wrote on Twitter regarding the quiz's image of King Sombra that was presented to him: "Interesting. I read about that in a script but never seen it before."

King Sombra is included in Hasbro's online game Crystal Empire Seek & Find as one of the items in level 5.

Quotes
"Yes... crystals..."

- The Crystal Empire - Part 2

"Crystal Heart..."

- The Crystal Empire - Part 2

"My crystal slaves..."

- The Crystal Empire - Part 2

"That is mine!"

- The Crystal Empire - Part 2

"What? No... No! Stop!"

- The Crystal Empire - Part 2

"Grrr..."

- The Crystal Empire - Part 2