When God threw the disobedient angels out of heven into hell, was it the angels or God who made hell such a nasty place? Assuming that part of the torment of those souls in hell comes at the hands of the demons, is that part of God’s plan or just a result of sin?
Theologically speaking, God did not “throw out” the disobedient angels. They chose to separate themselves from him. Given their superior intelligence and pure spiritual nature, their choice was permanent. The permanent, irrevocable choice to oppose God is the very essence of hell. For humans this choice is made at death.
What this means is that God did not create hell, he only allows for its possibility as a consequence of his choice to give angels and humans the gift of free will. In order for free will truly to be free, it must include the possibility that the free person can choose to reject God. That rejection of God on the part of the angels is what created hell.