So does that mean ianna and the red God is the same person???

Since they are coexisting?

there is this golden eyes demon or monster mention in the beginning of the story, I wonder if he can be Arhad, since Ianna can coexist with the red hair god. Arhad might coexist with that golden eye demon too. Since the beginning of the story the golden eye demons is mention every where, everyone knows the golden demon the what cause the end of god era.

that's possible