confidence trickster

:  a feeling or consciousness of one's powers or of reliance on one's circumstances

:  faith or belief that one will act in a right, proper, or effective way

:  the quality or state of being certain :  certitude

:  of, relating to, or adept at swindling by false promises

:  one who tricks: such as

:  a dishonest person who defrauds others by trickery

:  a person (such as a stage magician) skilled in the use of tricks and illusion