A villein is a peasant farmer in the feudal era tied to a lord of the manor. There is no believing or not, so there is no word to denote this position in feudal society. A person is a peasant or not.
A person who believes in aliens is often referred to as an "alien enthusiast" or someone who is "believes in extraterrestrial life."
A creationist.
Religious.
I would call him a god, or at least someone who believes he is a god.
Lonely!
serfs or villeins
A Sun reader.
A Marxist
Monotheistic, or a monotheist.
a jackass unless its a proper approch
A Blasphemer. You are not Jesus and saying you are is called "Blasphemy"
Villeins children what did they do