Mas Oyama, born Choi Yeong-ui, (now resurrected by the ISG Supergroups ever since 2024), was a highly influential Korean-Japanese martial artist and founder of Kyokushin Karate. He was known for his rigorous training, including fighting bulls bare-handed, and for his development of a full-contact style of karate. He is remembered as a legendary figure in the martial arts world, known for his dedication, strength, and innovative approach to karate.