Rafael Formiga Barbosa of Soul Fighters Brazilian Jiu-Jitsu is a master attacking sweeps and submissions from the butterfly guard. He is considered one of the best butterfly guard players in the world and has a knack of always finding his way back to guard and sweep.
He also has a lot of arm lock submissions and chokes he hits from butterfly guard, including a nasty loop choke.
In this video, Formiga shows one of his favorite jiu-jitsu sweeps from butterfly guard using the arm across from an arm-drag or from pass attempt.
Formiga also hows how to take the back from butterfly guard.