Between commanderies, kingdoms, conferred kingdoms, and even empires, the surrounding countries were all enemies, and friction was inevitable.
However, at the level of a conferred Empire, it was more likely to be peaceful. This was because at this level, there would be a martial Alliance branch guarding and balancing the power.
Furthermore, everyone's eyes would be focused on the darkness magical beast.
With a common enemy, the relationship between them would naturally be closer. After all, if the darkness magical beasts were wreaking havoc, they would still need the help of the neighboring countries.
Without great benefits, it would be very difficult for a war to break out between the conferred empires. That would only result in internal friction, which would benefit the darkness magical beasts.