The blood curse

Cali is born to a human father and a mythical being mother called engkanto. A cunning race of supernatural creatures who cannot procreate with their own, therefore they have to assume a human form for a year to find a mate and produce a half engkanto. they leave their offsprings once they are born and then return to them every 8years to tempt them to embrace the life of an immortal being instead.
The only problem is, once the offsprings crosses over, they lose their humanity and becomes an emotionless cunning creature just like their immortal parent.
Cali is turning 24 in 5 months, and her only option is either to die as a human, or live forever as an engkanto. Then comes viper, a detective who reopened the case of her missing boyfriend 8 years ago. Cali has to run away from the past, present and the future.