Complex sentence: Hoost is well known for training Knees of Fury Fighters Brad "BULL" Koek (RETIRED) and Paul Slowinski and is currently still training Paul Slowinski and under his guidance Slowinski has won the K-1 tournament 2007 in Amsterdam.
Split into simpler sentences: Hoost is well known for training "Knees of Fury" fighters Brad "BULL" Koek (retired) and Paul Slowinski (whom he is currently still training). Under his guidance Slowinski has won the K-1 tournament 2007 in Amsterdam.