Golden angle & the darkness of midnight

It is a mysterious novel that describes the friendship between a human being and an angel. Ravi met a strange girl and soon found their fates were tied. One day he realized that she was not from his known world. Ravi and Khushi are under the limelight in this novel. Their friendship grew and one day, Ravi discovered the mysterious part of her life. She was being kidnapped by a couple of witch and vampire, who wanted to create a new powerful clan after using her DNA so they could re-establish their 2000-year-old kingdom to capture the earth and fairyland.