The Allied Army is Decimated
The magic formation managed to agitate the dark god, but it also managed to stop its channeling. The dark swirling clouds in the center of the imperial capital became calm. The dark god wants to move from his position, but he cannot.
The barrier not only limited the dark god's sphere of influence on the imperial capital but also limited the spread of its domain. A dark god or any god would almost be impossible to beat inside its own domain. This is the reason why the dark god, Nyarlathotep, is not moving from its castle throne.
Despite treating others as ants, the dark god knew that the demigods surrounding him are waiting for their chance. The chance that they are waiting for is the dark god to move away from its domain. The moment the dark god even moves at least an inch away then they could damage it greatly.