The Benandanti are a secret society of mortals in the Classic World of Darkness who have developed sorcerous means of crossing over into the Underworld. Each Benandante, upon initiation into the group, forges a unique fennel sword that allows them to reach across the Shroud.
"Some older Hand members speak of mortals known as the Benandanti. They are humans capable of leaving their bodies and traveling into the Underworld. It is said that once, long ago, some of them walked the streets of Enoch in disguise and secretly studied in the libraries of the Tal'mahe'Ra.
Most Kindred have never heard of them, and most of those who have do not believe in their existence. They claim no living soul can enter the Underworld. Still, some fear valuable secrets were stolen by the Benandanti, which might be traded to others in the Underworld, leading to an attack on Enoch, or at least ending its peace."
Dirty Secrets of the Black Hand page 51