Pony of Shadows

Stygian, better known as The Pony of Shadows, is a villain from My Little Pony: Friendship is Magic, serving as the main antagonist of the Season 7 finale, "Shadow Play".

Background
The Pony of Shadows was originally a male unicorn named Stygian, who lived in Equestria 1,000 years prior to the events of the show. When Stygian's home was attacked by The Sirens, he summoned the help of the Pillars of Old Equestria: A group of six powerful ponies who had the power to defeat the Sirens. Their leader, Starswirl the Bearded, put an end to the Siren's reign by banishing them to another dimension, causing the Pillars of Old Equestria to be hailed as heroes, while Stygian when unaccredited for his actions.

Stygian begins to feel outcasted by this, and decides to use a spell to gain a better understanding of the Pillars of Old Equestria. However, this spell requires a specific item from each of the members, and his theft of these items leads the members to believe his spell is intended to steal their power. Angered, the Pillars of Old Equestria banish Stygian. Having been betrayed by his own heroes, hatred festers inside of Stygian, transforming him into the Pony of Shadows.

The Pony of Shadows attempts to attack the Pillars of Old Equestria, but they use their combined magic to seal him in limbo. This ritual also causes themselves to become trapped in limbo as well, so they plant the seeds for what would eventually become the Tree of Harmony to watch over Equestria in their absence.

Escape
The Pony of Shadows is inadvertently released from limbo by Twilight Sparkle, once she and her friends learn of Starswirl being trapped. In her excitement to meet her idol, she frees them all, including the Pony of Shadows. The Pony of Shadows then destroys the Pillars and Starswirl's spell book so he can't be sent back to limbo and attempts to attack Starswirl, however, Twilight and Starlight Glimmer counter his attack, forcing him to retreat to shadowy areas to regain his power. However, due to the industrialization of Equestria over the past millennium, many of the areas that were once known to be dark are now populated and have become brightly-lit cities, thus buying Twilight and her friends time to come up with a plan on how to locate and re-contain him.

Eventually, the ponies are pointed out by the castle's map the location of The Pony of Shadows; an abandoned ghost town on the edge of Equestria. They travel there, and the entire town collapses into the ground to reveal a temple, where the Pony of Shadows resides. They begin to use their magic to open up a portal to banish him, while Starlight attempts to urge Twilight to rethink their plan, believing Stygian can still be saved.

Defeat
As the Pony of Shadows begins to slip into the portal just like the Dazzling, Twilight hears a voice from within the black mass that is his body, and dives in. She meets Stygian, sitting alone in the darkness. Stygian explains the entirety of the situation to her and Starlight, who later joins in, and how he only wanted to become like his heroes. Starswirl and the Pillars, now finally seeing they're the reason of Stygian's transformation and that they were wrong about him stealing after hearing this from outside, use their magic to pull Stygian out of the darkness, as the Pony of Shadows is banished to another dimension. With the Pony of Shadows gone, the Elements of Harmony and Pillars of Old Equestria both intact, the land is at peace once again, and Starswirl apologizes to Stygian to rekindle their friendship.

Appearance


Before his mutation, Stygian was a weak, skinny unicorn with a gray coat and a blue mane.

After becoming The Pony of Shadows, he takes on the form of an amorphous dark gray Alicorn with glowing white eyes and wispy, smoke-like wings. His horn becomes large and curved, much like King Sombra.

In both forms, he speaks in an indistinct European-sounding accent. In his mutated form, his voice also has a filter effect similar to what Queen Chrysalis had in Season 2, albeit much deeper.

Stygian was reverted back to his original form after being separated from The Pony of Shadows.

Personality
Before becoming evil, Stygian was rather soft-spoken and non-confrontational. Rockhoof refers to him as "scholarly".

As the Pony of Shadows, he becomes much more arrogant and loud. He constantly belittles the Pillars of Old Equestria and mocks Twilight for unknowingly setting him free. Even until the moment of his defeat, he maintains his composure and acts unphased.

Trivia

 * At the end of the finale, The Pony of Shadows is banished to an alternate dimension using the same portal Starswirl used to banish The Dazzlings.
 * In Equestria Girls: Rainbow Rocks, it is revealed the alternate dimension they ended up in was the human world, meaning The Pony of Shadows may play a role in a future installment of the Equestria Girls series.
 * A mythical entity referred to as "The Pony of Shadows" was mentioned in the Season 4 episode, "Castle Mane-ia". However, this event is never mentioned in the Season 7 finale, so it is unknown of these two entities are one in the same.
 * Not to mention that the aforementioned entity was explained as being the accumulated hatred of Nightmare Moon, whereas the entity featured in Season 7 is something completely different.


 * The Pony of Shadows is very similar to Venom, as they were both normal individuals until they were transformed by a dark substance and are obsessed with revenge against certain heroes who they believed wronged them (The Pillars of Equestria for the Pony of Shadows and Spiderman for Venom).