What is the source of torment for Satan and his fallen companions ?

The reader first meets a stunned Satan chained down to a fiery lake of hell, surrounded by his coconspirators. In this first chapter, the reason for his downfall is that he thought himself equal to God. Hell, however, has not taught him humility, and, in fact, strengthens his revolve to never bow to the Almighty (Interestingly, the word "God" is not used in the chapters dealing with Hell and Satan).