Depths of Vanalf by Brady Hunsaker

“Depths of Vanalf" is the first book in the "Grimnir Chronicles" series, an epic fantasy inspired by Scandinavian folklore, The Witcher, and D&D. The story centers around Hallik, a young man training to be a Grimnir, a magic-wielder, on the island of Avskild. Avskild is protected by a shield, but when monsters breach it, Hallik and others must venture into the dangerous cave system of Vanalf to hone their skills and restore the shield.