Though aristocratic families in Etsey will refer to their familial and political house, passing down entailed property, estates, and surnames, four of those houses were also long, long ago Houses of the four Elements. Most Etsians, especially in the south, believe this is simply a story, though the northern half of the country believes it, as do all witches and alchemists. Members of the magical Houses possess in their bloodstream the elemental power of their House Element: fire, water, air, or earth.
In practical terms it means they are slightly more adept at being alchemists or witches and that their blood fetches a high price on the alchemical black market. In traditional (and, as it turns out, literal) terms it means they are biologically obligated to abide by the laws of their House daemon, the magical embodiment of their Element, housed in their family talisman. However, over the thousands of years since the formation of these Houses, disputes and artifice have destroyed all but one of the Houses’s financial and political powers, and two are wiped out completely. The house of earth and air were merged by (forced) marriage long ago, and shortly before the onset of The Seventh Veil the last of the house of fire was killed, leaving no more blood of that House whatsoever. The house of water survives, but only barely, as its sole remaining member has taken Apprentice Vows.
The House daemons are traditionally benevolent and helpful spirits, but should the members of the House attempt to use the powers of the Element for evil, the daemon becomes demon and consumes the offender, consigning their soul to an exquisite sort of hell. Of course, an important point in this arrangement is that the daemon itself is the judge and jury in defining “evil,” and despite thousands of years crafting lore about curses and intricate rules of who House members may and may not kill, cheat, or maim, the truth of the matter is that only the daemons themselves know the true definitions, and it is not known whether or not daemons can lie.