The Return of the Prince?

In the beginning there were two sisters, but was that truly the beginning of the sisters story? No.

In the beginning there were Unicorns, Pegasi and earth ponies alike living in harmony, but then a piece of the sky fell from the heavens above and touched the surface of the planet. Two magnificent Ponies arose from the crater and there names were Star Light and Galaxy Knight. Never before had there been any ponies like them, they had long majestic manes, beautiful wings and sharp horns. This new breed of pony came to be known as the Alicorn and as with all Alicorns they had extraordinary magical abilities. Star Light raised the sun and showed everyone what amazing power she had and upon doing this everyone bowed to them thus showing there respect for them. The ponies instantly deemed the two King and Queen of Equestria, making them responsible for the raising of the sun and moon and the well being of the land and all its citizens. Years Later the King and Queen had two beautiful daughters that were gifted magically and would take on the responsibility of raising the sun and moon. These mares were named Celstia and Luna and that is were the story began... but there was a secret that was hidden from everyone. The King and Queen had a son before the two daughters and unlike them he wasn't very skilled in magic. His name was Starbound Knight and he was the first born.

He couldn't even hold up a chalice to his mouth before his nose started to bleed from the strain of using his magic. One day, King Galaxy and Starbound went to the land that used to belong to the Draconequus for some flight training. Starbound took off like a rocket and amazingly the King could barely keep up with his son who was blazing through checkered landscape. Then something amazing happened, Starbound had performed the worlds first Speed Break (A Sonic Star-Boom) and he was so young when he did it. As the years went by Starbound Knight had only gotten faster and faster and then came the day his parents wanted to talk to him about his magical ability skills. They told him that when the time came he would have to take on the responsibility of caring to the needs of all the pony folk in the land but since he could not raise the Sun and Moon himself he would need help and so they planned to have two more children in hopes that they could raise the Sun and Moon for him. This would have made Starbound Knight the King of Equestria and his future siblings his Royal subordinates. So as the time passed Starbound learned all he could about running a kingdom and as time went on he grew more and more sad that he couldn't use magic to help his kingdom. Then came the day that the changed everything, Starbound learned that the consequence for using magic inside the castle was death by guillotine and had to be overseen by the King. He knew if he had to send someone to the guillotine for something like that he would be hated by his citizens and there was no way of getting out of his royal duties. Starbound went for a fly later that day and was so overwhelmed by the feelings of sadness and grief that he flew as fast as he could but without knowing it he had flew into outer space and judging by his surroundings he wasn't anywhere near earth. When he had finally made it back to earth by back tracking his flight pattern he went to the moon and looked at earth for a few moments.