Naag Nagin (1989)

Chandini and Kuber are shape-shifting snakes. Aghuri serpent wants to capture them for a Mani by getting which a person can rule the world and also attain immortality. But fails every time as they can recognize him when he is near. Rana and his man wants to get hold of a Mani so Aghuri uses them as a tool to capture Chandini and Kuber. Kuber gets killed in the mishap and tells Chandini where he has hidden the Mani. Kuber is reborn as Suraj and 21 years later he is in love with Rana's daughter Kiran. But she meets and marries Chandin. Aghuri finds Suraj is reborn if Kuber and Rana plan to kill him.