In Kengan Ashura, Tokita Ohma does indeed face a fatal outcome—he suffers severe injuries in his climactic battle against Kuroki Gensai and is presumed to die, departing with a peaceful smile on his face.
However, in the sequel Kengan Omega, Ohma is revealed to have survived. He’s brought back to life through a heart transplant performed by Dr. Hajime Hanafusa. Following this miraculous revival, Ohma spends time resting and recuperating at the Kure Village before reentering the fighting scene, taking part in Purgatory-related events and continuing his journey there.