Depiction in the comics
From past to present
In Reflections, the alternate Equestria's history is touched upon in the smallest of details, but what is touched upon suggests a history vastly different than that of the series' Equestria.
The alternate Equestria is described in Issue #19 as once being "lush... green and bountiful". King Sombra—an evil, power-hungry unicorn in the series—is a benevolent unicorn in the alternate universe who rules with kindness. Princess Luna serves as one of his advisors, and Princess Celestia is a tyrannical Alicorn villainess who terrorizes Sombra's pony subjects and seeks to take over Equestria.
Unlike in the main universe, Discord, the master of chaos, did not rise to power as shown in the season two premiere. In Sombra's Equestria, Discord is a knighted hero who is known by many as "Sir Discord" (or "Captain Goodguy"). Also unlike in the main universe, Princess Luna did not turn evil and become Nightmare Moon. However, she did become evil and join her sister when the normal Luna returned.
Discovery by Star SwirlSome time in the past, during his research into other universes, Star Swirl the Bearded discovered a way to travel to the alternate Equestria via a magical mirror and invited Princess Celestia with him on his excursions. During their first visit there, Celestia met and fell in love with the good and handsome King Sombra, and she and Star Swirl became briefly acquainted with his universe and how much it differed from their own.
Celestia and Star Swirl's visits to the other Equestria were at first infrequent. But after the main Princess Luna became Nightmare Moon and Celestia banished her to the moon, Celestia visited the other Equestria more often and without Star Swirl's knowledge, finding solace in her relationship with Sombra and the other Luna. Over time, distortions began occurring between the two universes, such as books disappearing in the main universe whenever Star Swirl borrowed books from Sombra. When Star Swirl found out about Celestia's secret trips through the mirror, he became livid and closed off the pathway to the other Equestria.
Celestia, deeply saddened that she wasn't able to say goodbye to Sombra, goes behind Star Swirl's back once again and successfully reopens the mirror, allowing her and Sombra to continue their relationship in secret.
A thousand years later, Nightmare Moon returns and is subsequently defeated by the Elements of Harmony. The main Princess Luna's return to normal causes the alternate Princess Luna to become evil. She joins forces with Celestia's evil counterpart, accelerating the other Equestria's decline.
Colliding universesCelestia later returns to Sombra's universe after having spent some time away, but she is attacked and brutalized by her evil counterpart, who seeks to conquer both Equestrias. Celestia, realizing that the two worlds have become too closely bound together, sends Twilight Sparkle and her friends through the mirror with the Elements of Harmony to defeat the evil Celestia and Luna. However, as the ponies soon discover, the evil princesses cannot be harmed without inflicting the same harm upon the good princesses. Thus they come up with a plan to imprison the evil princesses in crystal.
Before the ponies' plan can be enacted, evil Celestia turns on her own sister and attacks her with magic. This causes the good Luna to be thrown back against the mirror, shattering it to pieces. The rift between the universes finally reaches its breaking point, causing the sky to crack and the worlds to slowly merge.
Twilight and her friends use the Elements to trap the evil Celestia in crystal, but their plan means the good Celestia will be imprisoned as well. Thus King Sombra comes up with another plan: he uses the Elements to extract the alternate Celestia and Luna's evil and absorb it into himself. The alternate princesses turn good, and the alternate Sombra becomes evil just like the original.
The universes begin to repair, and the ponies return to their home universe before the walls between the worlds close forever. With the good King Sombra now evil, alternate Celestia and Luna assume the throne, and alternate Equestria is on the road to recovery.
CanterlotCanterlot is the capital of Equestria and home to the royal palace of King Sombra. It also has a hidden wishing garden for ponies to write wishes on slips of paper and tie them to tree branches. An annual event that takes place there is Sombra's Samba-Fest and Chili Cook-Off, shown on Friendship is Magic Issue #19 page 6.
PonyvilleAlternate Equestria's Ponyville is briefly shown throughout Friendship is Magic Issue #19. It is home to the alternate Mane 6 and Spike. Unlike main Ponyville's thatched cottages, alternate Ponyville appears somewhat more modern in design.
Castle of the Two SistersThe Castle of the Two Sisters serves as the seat of power for the evil princesses Celestia and Luna. Unlike the main universe's castle, which is in ruins due to Luna turning into Nightmare Moon, the alternate universe's castle still stands tall at the edge of the Everfree Forest.
- On page 3 of Friendship is Magic Issue #19, King Sombra mentions Equestria's north lands, which are protected from evil by Sir Discord, and its south lands, which are protected by Chrysalis.
- On page 16 of Friendship is Magic Issue #19, King Sombra states that Equestria's Pegasus cities lie in ruin as a result of Celestia and Luna's tyranny. A sheet of paper on page 3 reads "Cloudsdale in ruin".
- According to another sheet of paper on page 3, alternate Equestria has no Dodge City or Rainbow Falls.
- Friendship is Magic Issue #20 page 3 shows a signpost with eight signs, including ones for San Franciscolt, Whinnyapolis, Las Pegasus, Bitsburgh, and Horsolulu.
Other world differences
- The Elements of Harmony do not exist.
- The alternate Mane Six and Spike are wanted criminals, charged with "gum chewing, puppy hating, line dancing, jaywalking, cattle rustling, not returning library books, vandalism, line cutting, taking the tags off mattresses, taking candy from fillies, forgery, smuggling, not eating thier[sic] vegetables, being a public nuisance, and loitering".
- Some time in alternate Equestria's history, Trixie was crowned an Alicorn princess.
- Flim and Flam serve as fair Equestrian court judges.
- Alternate Equestria is shown to have a better understanding of the sciences.
- Alternate Equestria discovered coffee beans before main Equestria.