Un-Wol

He was the master of ChunWoo Han and Ryuji. After achieving the Black Origin Threshold the Martial Arts Alliance banished him to a life of meditation and solitude in a cave while he tried to figure out a way to solve the problem of this technique. He was always calm and composed and did not hold a grudge against the elders that exiled him. Despite almost never showing emotions he is very caring as he expelled Ryuji as a disciple and killed himself to protect both Ryuji and ChunWoo Han respectively. He is also very moral as he told off ChunWoo Han when his student made the wrong choices in using martial arts to hurt others. Source: The Breaker wiki