Complex sentence: Today, Mitose's influence is still present with the development of Total Force Freestyle Karate by B.J. Cook, a student of Renshi Vaughn until 2007, when he created this style of American Karate.
Split into simpler sentences: Today, Mitose's influence is still present with the development of Total Force Freestyle Karate by B.J. Cook. Mr. Cook was a student of Renshi Vaughn until 2007, when he created this style of American Karate.