Once upon a time Perceval...: A short story about the Grail for young readers

In this short story aimed at readers aged 11 to 15, freely adapted from ＂Perceval or The Story of the Grail,＂ written by Chrétien de Troyes (an author alive during the 12th century), we are introduced to the origin story of Sir Perceval, one of the Knights of the Grail (also known as Knights of the Round Table).
Told from the perspective of the great sorceress Morgana, we follow the story of Perceval, a young peasant who leaves his mother’s house for an adventure in the nearby forest. After some time, he finds himself in the middle of a battle at King Arthur’s Castle. With this, he begins a brief rite of passage where the young man becomes a knight with training and teachings conducted by his mentor, Sir Gorneman, and his beloved niece Blancheflor. However, before the final test to become a Knight of the Grail, Perceval pays a visit to the Fisher King that will change his understanding of the world.