It is called your inner voice. This decides what things you do and how you do it.
The literary concept you are referring to is called the "angel and devil on the shoulder" or more commonly known as a moral dilemma. It symbolizes the internal conflict between doing what is right (angel) and what is wrong (devil).
angel
angel was Gabriel, and Devil was satin
loser you are
The archetypical fallen angel is called the "devil".
Traditionally the devil would be on the left shoulder, due to the belief that the left hand saide was the evil or sinister side. But really, you can get them on whichever side you want.
The song is called Devil in Disguise. "You look like an angel Walk like an angel Talk like an angel But I got wise You're the devil in disguise Oh yes you are The devil in disguise"
They are called "halfbreeds"
Angel on my shoulder.
Devil on My Shoulder was created on 2009-08-26.
To deceive you. Satan was never an angel. He's a jinn who became a devil.
Angel in a Devil's Body was created in 1983.