Throughout this verse Z1 has been digging and trying to figure out the root of earth’s evil. He finds Satan and beats his ass. In this line Z1 is saying money is a key tool Satan uses to entice people into demonic mind states.
Medusa, in Greek mythology was a monster with the face of a hideous human female and she had living venomous snakes in place of hair. If directly looked at, she would turn onlookers to stone.
Z1 is using stone as a symbol for cold-hearted people. People with no feeling and would do anything to get what they lust for without thinking or simply caring about the affect it could have on the people around them. This characteristic can sometimes be used for people when money is involved. Which is why Z1 says “Niggas turn to stone like Medusa’s face is on the prints.”