The word "demon" should be seen as describing someone who is more controlled by daemons than their own will.
A demon may also be considered a soul (a player behind an "account (soul)") who is in the process of becoming physical, or volunteering for the role of being something akin to an "NPC" -- a "non-player-character" or "background person."
Someone who is more run by daemons than they are by their lucid awareness can be considered a "demon." In other words, someone who functions more on automated responses or decisions is demonic. A demon is an agent of the physical world. They are synonymous. The demon obeys the physical world and is its messenger. It has no agency of its own. It is compelled by physical demands. You may even consider the physical world as its collective, its master, or a gestalt from which it receives orders.
If there is a soul beneath the 'demon', it is suppressed by the collection of its own daemons and can be considered "asleep." The soul is not able to effectively exert its will without first dealing with the demands of its own daemons.
Anyone who has authority over the physical world can control countless "demons."
Demons may also be considered doppelgangers or mimics, as they have very poor understanding of concepts like empathy or compassion and instead must emulate these traits. Demons are will generally become sociopaths or narcissists, as they either become like vampires who cannot see themselves in the mirror -- or become so enamored by the mirror, they no longer see a reflection and so treat everyone like they own them.
You cannot deal with a demon the same way you deal with a "normal" person. As an agent of the physical world, the demon is as dangerous as a poisonous snake, or an avalanche. You cannot make the mistake of thinking it deliberates, or contemplates or functions with ethics or morals in exchanges with you. You do so at your own peril, much like handling a wild animal.
It has no qualms or stipulations of breaking laws whether these are man-made, or