BJ is the first American to win the Mundials as a BLACK BELT. My current coach won the No Gi Worlds as a brown. His black belt, Kai, is a two time Mundial world champ, but at Purple and Brown. His brother, Kendall won the Mundials as a blue and purple. Egan Inoue won as a blue and purple as well. Of all the Mundial winners from Hawaii, BJ is the only one to do so at Black belt (And any other American). Hawaii has produced six Mundial champions.
Serra took second in the prestigious ADCC submission championship. In the process, he beat Takanori Gomi, JJ Machado, Leo Santos. He lost to Maricio Feitosa in the finals. (Another Gracie Barra fighter).
Serra is Renzo Gracies first Black Belt, though.