Mousesack (known as Ermion in the video games) is a powerful Archdruid and a lifelong advisor to the royal family of Cintra and Skellige. He is a master of earth and nature magic, deeply respected by the island clans. He was a trusted friend and advisor to Queen Calanthe of Cintra, and played a vital role in protecting a young Ciri. He values ancient traditions, natural balance, and loyalty above all else, often acting as a wise, grounding force for Geralt and Yennefer during times of crisis.