King Sombra

King Sombra is a unicorn who's heart is black as night and once took over the Crystal Empire. He is the father of The Nightmare Family. And is also the main antagonist in the series.

Backstory
King Sombra is a unicorn whose heart is said to be as black as night. He took over the Crystal Empire and enslaved the crystal ponies, before Celestia and Luna overthrew him, turning him to shadow and banishing him to the Arctic North, disappearing into a crevice of ice which closed up, but not before he put a curse on the Crystal Kingdom that caused it to disappear for a thousand years.

Eventually the Crystal Empire reappeared, but the crystal ponies had no memory of their kingdom before Sombra took over, and the mere memory of him causes them pain. Sombra returned along with the Crystal Empire, and tried to attack it again. Princess Cadance cast a protection spell around the Crystal Empire.

When Twilight Sparkle, Rainbow Dash, Fluttershy, Applejack, Pinkie Pie, Rarity, and Spike came to the Crystal Empire to protect it, Sombra chased after them in shadow form, but they got through the barrier, although he attacked Shining Armor he survived, but his horn was cursed so that he could not use magic.

When Cadance began to run out of power to perform the spell, the barrier briefly deactivated. Sombra's horn was broken off as the barrier reactivated, and he transformed it into a dark crystal which began to create more dark crystals in the Crystal Empire.

Twilight and Spike searched for the Crystal Heart, the key to protecting the empire, inside the castle, where nopony would dare to look. They ran into a door enchanted by Sombra to confront them with their worst fears. In Twilight's case, she thought Celestia told her that she failed her test and wouldn't continue her studies. After snapping her out of this, Spike thought Twilight was sending him away, but Twilight realized what Sombra was doing.

Eventually they reached the Crystal Heart, but Sombra, able to invade once Cadance was no longer able to perform her spell, trapped Twilight in a wall of dark crystals, keeping her from the Crystal Heart. Twilight told Spike to take the Crystal Heart to Cadance. Returning to his physical form, Sombra tried to spear Spike with a dark crystal, but Cadance saved him from the attack. She then returned the Crystal Heart, and together with the crystal ponies used its power to unleash a wave of magic that restored the Crystal Empire and destroyed Sombra, shattering him to pieces.

Bio
Later, when Nightmare Moon came, he fell in love with her and married her and spread fear all over the world.

Personality
Compared to other villains on the show, King Sombra's personality is not too elaborated on. Instead, he is little more than a dark, looming menace for most of the episode. He has very few speaking lines, some of then half-incoherent, and is a very mysterious character, whose backstory is limited to the fact that he enslaved the crystal ponies. The source of his dark powers and his motivations remain an enigma. He is however shown to be extremely cruel, fierce and sadistic, viewing crystal ponies as nothing more than his slaves, using fear on them and other characters, and licking his lips as the prospect of possibly kill Spike (although he may have primarily been after the Crystal Heart).

Sombra appears to be very intelligent, as he seemingly thought ahead of his enemies and placed a curse upon the empire to disappear if he gets defeated, and he cleverly booby-trapped the way to the Crystal Heart. He ended up outsmarting Twilight as she fell for every one of the traps, more than one of which would have defeated Twilight Sparkle if not for the presence of Spike.

Powers
King Sombra appears in the show as a being of pure darkness. Due to this, he appears to be virtually impossible to damage via targeted magic, easily dodging Shining Armor's magic beam. However, he cannot penetrate some magical barriers, as he was unable to touch the Princess Cadance's field of love magic without getting harmed. His dark form can spread to immense distances, to the point that he can surround the Crystal Empire all by himself. He can also sink the ground and travel this way, leaving a trail of sharp crystals in his path.

Celestia states that she and Luna were the ones responsible for turning Sombra into shadow. This may imply that, albeit formidable in his present state, he could be even more powerful in his true pony form.

King Sombra's main power seems to be creating dark, jagged crystals. Those can serve as sharp weapons or imprison his enemies. If he engulfs a unicorn pony in his darkness, he can cover their horn with crystal, blocking off their magical abilities.

King Sombra's unicorn magic is unlike any other previously seen on the show. It is inferred by Celestia to be dark magic, powered by hatred and fear. The glow associated with it is a toxic purple bubbling. Though it can be cast by others, Sombra seems to be the main practitioner of it. It is affiliated with corruption, able to taint the Crystal Empire in a matter of minutes. In addition to creating dark crystals, this magic can also be used to show one an illusion of one's greatest fear, or even counter teleportation magic.

He also has huge knowledge of the Dark Side of The Force and he weilds a Darksaber, a rare, dark sword-like lightsaber who only dark lords wield.

Weaknesses
As a villain affiliated with hatred, fear, and despair, his greatest weakness appears to be the power of love, joy, and other such positive emotions. He is thus unable to penetrate Princess Cadance's magical love barrier without getting harmed by it, and is destroyed by the Crystal Heart, an artifact powered by positive emotions.

Main Weaponry

 * British Sten sub-machine gun
 * Darksaber