Black mages thought that gods had been created by humans. This point alone exemplified that black mages were the most presumptuous people in the world. Even the ancient humans had not had such thoughts.
However, even though black mages were arrogant, they had the right to be. Back in the early days when the black mages were going through a period of chaos, they had managed to deal severe damage to the mainland. And the reason they could do that was because they really had created a god, and more than one at that.
All of these gods were derived from the negative emotions found in all humans. Each god possessed the ability to cause immense destruction.
Abominable devil, terrifying devil, soaring devil, dark sky devil…