The Domain of Blood is not related to any Rule powers power or the domain-related abilities. It is simply a manifestation of one's killing Intent.
Though I and others are seeing blood-red everywhere, it is not. It is just our killing intent reacting and showing us the blood-red world of the Killing Intent my mother is emitting. If I looked through the camera of my holowatch, everything would be seen normal.
Mothers killing intent had erupted and it became completely focused on the group led by Old man. There are only four people in the Old man's group, including him, and to my surprise, all of them are Tyrants.
Seeing the killing intent being directed at them, three people around the old man covered themselves in their energy, only the old man remained unaffected by this massive killing intent as he stared directly into the vengeance filled eyes of my mother without flinching.
