Logan's statement about the possibility of a Demon Domain Ritual was not something that could be said lightly. Everyone knew that the chance of it being done by the demons was minimal, if not the demon generals or the demon lords themselves who came to execute the ritual. The risk for the ritual to be carried out successfully was more significant for the demons for several reasons.
The first reason was that they had to make several magic formations, or we can simply name them tokens, six to be exact, surrounding the territory they would take over. They had to guard these tokens for some time until they were entirely ready to be executed. The existence of these tokens would also drain a lot of energy from the demons guarding them, which would also be very easy for their opponents to detect.