Back in 2014 I had the pleasure and honour to train with UFC 4 fighter and Carlson Gracie black belt Daniel Vianna. Daniel fought against Matt Hughes and lost because of referee stopage due to cut.
This summer camp was amazing. I was 2 stripe blue belt by then and not so athletic coming out of my overweight phase and Daniel offered me the opportunity to roll with him. Then he proceeded to introduce me very gently to the "knee to the soul" technique as I called handling me without using his hands and without putting to much pressure on me.
Training with him was a big motivation for me up to this day.