Seijuurou

The last member to join Ruuji and his group, he is a reclusive swordsman who saves Ruuji from a group of wild Elephander Zoids. Although originally a warrior who sought fame and glory in Zoid battle arenas, he retired when he accidentally killed his pupil in a Zoid tournament. Prior to his early retirement, he was regarded as the strongest Zoid pilot in history, having won the tournament consecutively for 10 years. Quiet and aloof, he is the most skilled combatant of Ruuji's group, and reluctantly agrees to train Ruuji on their journey. He's suspected of having a serious health matter as he sometimes suffers from breathing and abdominal pains. Kotona is the only one who notices his suffering as he hides his private problems. Seijuurou pilots the Zoid "Soul Tiger".

(Wikipedia)