Demon spirits are not necessarily evil in nature.
Depending on their mood, they could be good and kind— the type who helps people when they get lost in the woods. They could be as playful as neighborhood boys who play tricks on unsuspecting victims or a big bad bully who causes harm to others.
Depending on their interest and feelings, demon spirits could be anything they like and do anything they want.
Like humans, they are beings that follow the flow of free will.
The only difference that could be noted between humans and demon spirits is their origin.
While humans are created and molded by the hands of God, demon spirits are born from nature.
They are either beings who originally had physical non-human bodies who gained intelligence and sentience through cultivation or spiritual beings who took form from the lingering residue of what was once life.