Mara, often short for Mara-Papiyas, is the lord of the sixth heaven of the Desire Realm and the head of gods in Mount Meru. It is said that if a man could reach beyond the sixth heaven, he will then overcome all kinds of desires and delusions to go on the path to enlightenment. So there is only a line between the Buddha and the devil!
I hope the two sister got kidnappd and rapd until their mind broken, and then the MC got revenge development with her cousin, to revenge the people who kidnappd her sister.