Abyss.
As the ritual in the mortal realm began to operate, the nine overlapped worlds within the Abyss felt its resonance.
Unlike the Spirit Realm which corresponds directly with the surface and material worlds, if Hell and the mortal realm were to open a passage between them, a coordinate, an anchor point, was needed to connect the two. The ritual layout by Mephisto was undoubtedly such a marker.
It originated from the hand of Asmodeus, who as a former god of time and space, still had a profound understanding of it. At this moment, as the sensing with the coordinate became clearer, an illusory portal slowly emerged on the second layer of Hell.
Rolling lava churned across the land, influenced by the Flame Kingdom, some volcanoes and magma slowly came into existence within the Nine Hells. At this moment, Asmodeus and the former God of Meteorology, Crius, stood together, watching the illusory light gate gradually solidify.