Ridley Duchannes is Lena's Dark Cousin who she grew up with until Ridley's sixteenth moon and darkness claimed her. Ridley is a succubus and as we go through the sequel to Beautiful Creatures, you can really see that Ridley doesn't want to be dark. She walks Ethan and his clan through the tunnels to get to Lena before Sarafine can claim her to the dark. Sarafine, being an extremely powerful natural, meaning she can manipulate nature, gains power and as a punishment to Ridley for helping Ethan, strips her of her powers and makes her a mortal girl.