Fan Casting Stories of Undertale (Pilot)

Once upon a time, there was 3 people, Anton, Margaret & Tiff. Margaret & Tiff have been two sisters. Anton tried to marry Margaret, but she declined his words. Anton has Married Tiff, and they decided to build a Mirror Realm (to be called as Overworld). Margaret was all alone, until Azrael came to her. These hearts are fully aware to redo. Both Azrael & Margaret build Underworld together and are fully married. After the marriage, danger has turned. All Monsters are locked in the houses where Ancients are attacking. Azrael told Margaret if she will give birth after the attack, it would be a last chance. The only one who can stop the Ancients from Mirror Realm, is one and only, Princess of Undertale.