If not for the castle shaking, Fraser would have been laughing at Amelia for talking about demons. He truly believed that she was a witch or something close to it. He didn't know if she had always been one or if something happened to her in the north. The castle shaking was enough evidence for him to have her set on fire once he got rid of her guards.
"Get the princess!" Fraser ordered the Blackwell guards. They were wasting time standing around here while Amelia stood by his throne. "Kill all of her guards."
He would rid the castle of anyone from the north.
Agramon's laughter as he left the darkness where he previously stood to join Amelia, stopped the Blackwell guards from attacking Amelia. He was always amused by how bold humans could be. Easily dismissing the existence of demons when they were in this world longer than humans.