When Tessa moved, Anderus moved with her, [b] " Tessa, don't move! You should stay in the center of the imaginary sphere!" [/b] Anderus shouted to her, he was working in an ancient protection technique where the person who needed the protection is standing or sitting in the center of an imaginary sphere and the fighting monk or monks move on the surface of that sphere, blocking attacks and inflicting damage to the trespassing enemies.
When Tessa fired that bolt of lightning, all the bandits concentrated on her, Anderus had to add kicks and bites to his "Butterfly dance" in order to handle the pressure.