Who is Bidhata Purush from Sister of My Heart and what is their importance?

The Bidhata Purush is a god who supposedly visits each Indian baby the night after they are born to write their fortune on their forehead. It is also believed that the Bidhata Purush writes the date of a person's death on their forehead at birth. Some Indians seem to believe that their entire life hinges on what the Bidhata Purush writes on their forehead. Pishi credits the Bidhata Purush with allowing her to be a mother to her nieces.