The Empire was always a threat to the other kingdoms, before the shadow continent even existed they had attempted to conquer each kingdom one at a time, it was only because of the Shadow that the Empire had formed an alliance. Now that there no longer was the Shadow to worry about, the kingdoms were half expecting something like this, especially since they had refused to attend any of the meetings.
However they didn't expect an entire kingdom to be destroyed in a single night. The other kingdoms were already panicking, thinking that they wouldn't survive an attack and that their only hope was the group of Redwings that had destroyed the Shadow previously.
Inside the council room, the leaders were busy making their cases and deciding what to do, the only piece of information they had was that the Empire had used a piece of strong ancient machinery in their attack.
Luckily, the contraption seemed to take some time to move to the next kingdom.