Too bad there is no 'all of the above'.
I believe that God made everything, and is continually making everything, creating by extension. We are God's expression, and have creative potentiality as God gave/gives it to us. Therefore, demons, as we think of them (I don't want to get into etymology and all of that) are beings with an extraordinary capacity to test us and to force us to evolve. Do we create them? Maybe we cocreate them- in a collective sense.
MO, of course.