Headcanon
some more! The first one is crossover in fact... btw sorry again for bad enghish and pls review your ideas and comment. PM open too!
Remember the Tales of Beedle the Bard in Harry Potter? In fact, all the stories are based on some never-told, Greek and Roman myth. Those stories were extremely old and written down by a powerful fairy. The fairy is Alex and Conner's grand-grand-mother. She discovered the ancient Greek and Roman when the door between two world was accidentally opened. The time in the otherworld is slower before the birth of the twins. The door opened twice in the fairy's lifetime and it was between years. Those years were long enough for Greek civilization changed to Roman's. That's why she could record both stories. She record those stories and kept them down. Later, just before the death of the old fairy, she invented a spell to make objects transfer to the otherworld, to the greatest magician in the world of the time. The four founder of Hogwards got the book, and speaded the stories out.
Mr Bailey, the twins dad died when they were twelve. As a fairy, he returned to magic. After this, he found he can still think, move, see and hear! But not as a man, not as anything but magic flowing in the air. He was like air and could go to anywhere, just by think of that place. He realised that years passed by by the time he became magic, flowing in air. He could give magic power to someone who was able of it, and, if he tried very hard, he could whisper into one's ear. He thought of his son Conner(well, he believed Alex could take care of herself better than Conner did) and found out he was saving the would. At that moment, Conner was trapped in book. He was finding a way to get out by making the potion. One of the ingredient was magic, and Mr Bailey knew by heart that unluckly, his son didn't inherit a lot of it. He whispered, told him the key to 'magic', and gave all his power to his son. He became nothing, but happy that he could help his son at last.