Father Pavel
Father Pavel escaped communist
Russia in order to become a priest,
and later an exorcist.

Bobby Singer asked him to look in on
Sam Winchester, and found him trying
to exorcise the wrong sort of demon.
Since then he has taken the young
man under his wing and taught him.

He has become mentor, confessor,
and friend to Sam, as well as Singer's
eyes and ears to the true state of
Sam's soul.