Battler is Rudolf's 18-year-old son, and the main protagonist of the series. Although stubborn and hotheaded, he is a very compassionate young man. He tends to flirt with young women and has a perpetual fear of "shaky" transportation, thinking he may fall out of a plane or boat depending on the turbulence. Due to his father's remarriage, Battler rebelled and went to live with his maternal grandparents for the next six years, cutting all ties to the Ushiromiya family. After his grandparents' deaths, he returned to his family, though he had not fully reconciled with his father. He is greatly influenced by Kyrie's "flip the chessboard" mindset, which allows him to predict his enemies' thoughts based on the situation at hand. He has a habit of saying Dameda, zenzen dameda ("It's useless, it's all useless") when in a difficult situation. One of the main themes of the series is Battler's disbelief in the existence of witches and magic when his family and friends are murdered in the mysterious ways. Though he is convinced that the culprit is human, he is reluctant to suspect his loved ones as the culprits.