The survivors banded together calling themselves the "Mirror Family", I suppose in honor of their deceased lord's family?
Christopher->Anthony is Alfred's chosen successor. That complicates things with Kate, unless she's fine with not being the true heir and head of the Mirrors House. Her "little brother" is also far more driven to play "ruler" than his "big sister" is.
"No parent could send their son knowingly to his own death"
Says the man who effectively left his pregnant wife to her (seeming) death. He's speaking from his own guilt at failing to find her. His son says he couldn't give up on her, but I did not see him actually trying to look for her. It seemed more like a mental hangup rather than a genuine attempt at looking for his missing wife and child.
"Uncle Joseph"
He calls that man uncle rather than grandfather, that's interesting. We knew Anthony was a psychopath, but he really murdered his own father, who in any case was dying of old age in a few years, that's next level psychopathy. That means Kate is unsafe with him around, given his ruthlessness, she's likely seen as a competing pretender for the struggle to restore the Mirrors House.
Joseph is absolutely not the final enemy, if he is going to be an enemy. It's Anthony who has plans to be the ruler of the island after the Shadows House is brought down. I can already imagine some kind of succession struggle with Kate after the Shadows are brought down, if Anthony were to have his way.