Regarding Shadow of the Magic Dragon

Here, I'll mainly discuss the foreshadowing the author planted regarding Shadow of the Magic Dragon:

Volume 1, Chapter 7 of this book:

Born Noble: Wizard Genealogy once mentioned that the Shafiq Family descended from a branch of Merlin's mortal enemy, King Arthur's half-sister—Morgan le Fay, the Dark Witch. Historically, the Shafiq Family had produced a formidable figure known as the "Dark Queen." It was said that the villainous dark witch Maleficent in the Muggle fairy tale Sleeping Beauty had been based on this Dark Witch of the Shafiq Family.

Regarding Morgan le Fay:

In early literary works—namely the most orthodox Arthurian legends, written in the 10th century—Morgan le Fay was actually a positive figure, the healing mage who cured King Arthur. This clearly did not match the description of a "Dark Witch" in the Harry Potter universe, so it was not adopted. (Morgan le Fay's Chocolate Frog card explicitly identified her as a Dark Witch.)

Works in which Morgan turned evil only began to gain popularity after the 15th century. This was connected to feminism at the time, but deeper literary and social analysis will not be discussed here.

In T. H. White's classic Arthurian novel series, the four-part The Once and Future King, the first book, The Sword in the Stone (1938), depicted a Transfiguration battle between Merlin and his mortal enemy Morgan le Fay—though the book used alternative spellings for their names, Merlyn and Mim. This Transfiguration battle could be considered a classic of combat writing.

Both combatants were polymorphic Animagi, so when one turned into a mouse, the other became a cat; when one became a cat, the other became a tiger. The battle gradually escalated from there.

In the end, Morgan transformed into an invincible magic dragon. But instead of growing larger in response, Merlin thought in reverse and became the smallest thing possible—a bacterium. He covered the magic dragon's body in boils and red spots, gave it a fever, violent coughing, and more, until it finally died.

Thus, Morgan's most representative Transfiguration was the magic dragon.

Regarding the villain Maleficent in the Muggle fairy tale Sleeping Beauty:

In Disney's animated Sleeping Beauty (1959), Maleficent ultimately imprisoned the male lead, Prince Phillip, within the Forbidden Mountain, preventing him from reaching the castle to save Sleeping Beauty. With the help of three fairies, Prince Phillip escaped and also received the Sword of Truth.

Prince Phillip then forced his way into the castle, overcoming the many obstacles along the path. Maleficent had no choice but to act personally, transforming into a dark magic dragon in an attempt to kill Prince Phillip. In the end, Prince Phillip hurled the Sword of Truth, piercing the dragon's heart and killing it.

Thus, Maleficent's most representative magic was transforming into a magic dragon.

In summary: the Shafiq Family's bloodline inheritance was magic dragon Transfiguration—the forbidden domain of Animagi from 1991 to 1997: magical creature transformation.