ponies gathered around bonfires to eat, drink, sing, dance and tell stories until around midnight when the summer meteor shower occurred.
The stories told around the bonfires ranged from love stories, silly, drawn out jokes, epic tales, and of course ghost stories. However one of the stories that really stuck in my head that first festival was Scootaloo's
The filly started spinning this outlandish, over the top, but still interesting take on Princess Luna, Nightmare Moon, her sister Princess Celestia, and the Elements of Harmony. In Scootaloo's story Nightmare Moon's final goal wasn't just to cause eternal night. The demon had plans to create its own unique body/form, and then raise an army of undead ponies to help her conquer Equestria.
Nightmare Moon initially succeeded in the first part of her plan, refusing to lower the moon, but failed in her second part because Luna was stilling battling the demon mentally. Trapping the demon in her alicorn form. This gave Celestia time to activate the Elements of Harmony and put her sister and the demon into stasis on the moon while the Princess of the Sun grappled for a solution.
A thousand years later Celestia was still searching for an answer when the spell imprisoning Nightmare Moon/Luna failed and the demon was released from stasis. Quickly the demon abducted Celestia and imprisoned her the sun. But Luna was still struggling against the demon's attempts to gain supremacy and its final freedom. Unfortunately the Mane Six didn't realize this at the time and when they blasted Luna/Nightmare Moon with the Elements they inadvertently stunned Luna giving the demon the chance to escape from the alicorn's body.
Suddenly free from Luna's body, and temporarily stripping the alicorn of much of her power, the demon cast its great spell. Across the lands of Equestria millions of undead ponies starting rising from the ground. Local defenses and governments quickly were overwhelmed by this sudden onslaught. Canterlot fell to this terrible new enemy.
So now most of Equestria was ruled by the demon Nightmare Moon and her undead army. Any ponies who died resisting just joined the ranks of Nightmare Moon's army of undead. However the demon didn't slay everypony. For Celestia succeeded in escaping her imprisonment and was able to deny Nightmare Moon her eternal night.
This was a significant setback to the demon because her undead did not perform during well under the light of Celestia' orb. Therefore Nightmare Moon unable to turn everypony into an undead minion. These ponies were needed to work during the day as struggled to fulfill the demon's evil wishes and needs. However this meant that ponies could, if they were lucky, escape from her shackles. Once free they could seek out others who'd also escaped.
A few parts of Equestria still held out against the undead armies. Enclaves of earth ponies and unicorns had hastily erected subterranean strongholds that were now growing into Zion-like cities from the Matrix. Cloudsdale still held out and the pegasus ponies were using the weather to thwart Nightmare Moon's forces. The city was also where Celestia and Luna's government-in-exile was. From this base of operation Celestia was determined to free her remaining subjects.
One of Celestia's most valuable assets in this struggle was the fleet of airships that had escaped Canterlot. From the bridge of the gilded sky gallon Solar Flare Celestia along with her still recovering sister sail the skies of Equestria searching for ways to aid ponies that are still trapped under the yoke of Nightmare Moon's tyranny. Her crew of volunteers includes the Mane Six and of course the CMC. Together they've fought many battles, had numerous adventures, and faced countless perils!
In Scootaloo's story Celestia had become this Captain Harlock type character; right down to the scar and the eye patch. I just made her anthropomorphic for this drawing.