What does The Black Road represent

The Black Road represents a crossroads between one’s old life and a new one. When Casiopea and Martín are forced to travel it as champions of their respective gods, they can never go back to their old lives. They must either embrace the new life that they have been given, or wilt in the life they have left behind. This is the same for everyone who walks the Black Road, as each one is passing on to a new life in the Underworld.