I am not sure but I thought that RUMPLE was the beast after he became the dark one, but before Snow and James marry and have Emma.
In his first story he is a serf who is subjucated to the Duke, he had no power. After he kills the dark one he takes the duke’s money and power; RUMPLE goes off to live in a castle on his own and that is where Belle finds him. Their story plays out but RUMPLE looses Belle. … then he goes on bitter about love and he goes on to other bargains… Cinderella and Snow’s stories.