John Will completed his blackbelt under one of these men, a brother renowned for his BJJ skills?
Jean Jacques Machado
Title: Filippo Negroli
Passage: Filippo Negroli (ca. 1510–1579) was an armourer from Milan.  He was renowned as being extremely skilled, and may be considered the most famous armourer of all time.  Working together with his younger brothers Giovan Battista (ca. 1511-1591) and Francesco (ca. 1522-1600) in the Negroli family workshop headed by their father Gian Giacomo Negroli (ca. 1463-1543), Filippo was specialized in repoussé of armour, whereas his brother Francesco was renowned for his damascening skills.  Filippo's pieces are considered especially remarkable because they were wrought in steel, rather than the more-easily worked iron that was the traditionally assumed medium.
Title: John Will
Passage: John Will (born (1957--)16 1957 ) is a notable martial artist from Australia.  Will won the "Best Exponent Award" in the first World Silat Championships held in Jakarta in 1981.  Will also completed his black belt in Brazilian Jiu Jitsu under Rigan Machado and his brothers, John, Roger and Jean Jacques Machado in 1997; making him one of the first twelve foreign nationals to have earned a black belt in Brazilian Jiu Jitsu.
Title: Jean Jacques Machado
Passage: Jean Jacques Machado is one of the five Machado brothers, including Carlos, Roger, Rigan and John, renowned for their Brazilian Jiu-Jitsu (BJJ) skills.  Nephews of BJJ co-founder and Master Carlos Gracie, the brothers learned the martial art from an early age.
John Will Jean Jacques Machado