Das Vermächtnis der Wandler (The Legacy of the Shifters).
Carag's Transformation (The Woodwalkers Book 1) - Amazon.com
The "7z" in your request likely refers to the in her overarching walker universe, which is the first book of the sequel series: Woodwalkers: The Return (Season 2), Volume 1: Das Vermächtnis der Wandler (The Legacy of the Shifters).
After the events of the first six books, Carag and his friends face new challenges as they mentor younger shifters while dealing with lingering threats from those who oppose their kind. The Wider "Walker" Universe
Clearwater High, a secret boarding school for shapeshifters.
Katja Brandis (the pseudonym of German author Sylvia Englert) is best known for her high-stakes, shapeshifter fantasy series, which are popular with readers aged 10 and up. Her work typically follows young "walkers" who can transform between human and animal forms as they navigate secret boarding schools and environmental conflicts.
Brandis has built an extensive world through several interconnected series:
