The above lore bit explains a few things in the upcoming scene. The Immortals shaped the world of Aion, and dust magic is how they did it. Since Winter already has experience with spellcasting through dust magic, she'll be able to help the player characters understand the concepts of mana magic up to a certain point. However, due to the limitations of her magic, her experience will only take her so far. Spells of moderate complexity will be beyond her ken, and we'll have to develop those on our own.