Complex sentence: Brass spends most of her time helping out in Erika's journalist career, acting as the camera girl, and so she rarely fights; however, when she does robattle, she is a tough opponent.
Split into simpler sentences: Brass spends most of her time helping out in Erika's journalist career, acting as the camera girl, and so, she rarely fights. However, when she does robattle, she is a tough opponent.