It never happened

Luna awoke with a scream. It had happened again! She had become nightmare moon again! And she had won! She shuddered, she was so glad that though it could have been real Twilight had obviously stopped. A time paradox, that was all it was. She also had memories of other, horrible alternative worlds. But the Nightmare moon one was the worst. She had gone through it all again. She had banished her sister on the moon! She couldn't believe how cruel she was. How her sister must have hated her. Her sister! Celestial! She still had the memories too!

Luna lept out of bed, wiping away her tears. She needed to make sure that her sister was alright.

Luna quietly pushed open her door and crept across the hallway. She did not want the gards to notice her, as they would not remember anything, and she did not want to explain her tears. Doubtlessly they would not believe her anyway.

She crept up to her sister's room and put her ear against the door; she could hear muffled sobbing.

"Celestial!" she breathed, and pushed open the door. She crept in and closed the door, before Celestial noticed her.

"L-lulu? What are you doing here?"Celestial said.

Celestial had called Luna by her pet name, which meant that she couldn't hate her.

" The same reason, I shall assume, that your crying, i-it happened all ov-ver ag-gain! I turned into Nightmare moon and banished you!" Luna lept up onto Celestia's bed and and hugged her. Celestial hugged her back.

"And the one where Sombra killed you, I thought you were gone forever!" Celestial whispered back.

They kept at this for awhile, swapping stories and taking turns comforting each over.

Finally Celestial said:

"At least it never happened..."

"That won't make the memories go away, though it's better than if it had," as Luna's only reply.

Indeed Equestrian would have been in trouble if Twilight had not saved it.