Yonaas
This first chapter is quite interesting and we see the personality of the Lord of Demons--a ruthless person who will eradiate anyone who stands in his way. The main character on the other hand, a loyal subject to him. It seems that the change in Zephyr's attitude when Balthyrow wants to kill him was kind of sudden, from a loyal subject to suddenly a biting dog. Maybe you might want to go deeper into the reason why Zephyr became that way in the later chapters, and also show more personality later. Overall, good start and we could see the many possibilities of how this would go.