I don't understand, when he said Kaya family have spectre, does he mean Kaya family like her grandmother is originally a human but because she have special powers, her soul turning into a spectre little by little, and for Kaya's case her soul is now fully spectre because she uses her power since she's little?
Or did he mean they have this one big spectre as a "pet" and this spectre is taking over Kaya's family like her grandmother and Kaya by replacing their soul with its spectre part little by little?