Household Vassals are player characters or NPC cohorts/followers/companions who are granted the ability to borrow the power from a dungeon artifact holder. The dungeon artifact holder chooses a vassal, and the vassal must be able to accept the link, and therefore cannot be unconscious or dead. Charmed and Dominated characters can likewise not become a household vassal as they must accept the link of their own free will. A dungeon artifact holder can only have a total number of household vassals equal to their Charisma modifier. Benefits granted are tailored to each vassal's unique abilities, so two vassals are unlikely to have the exact same effects though they could be similar. For example a water-based dungeon artifact might grant ice powers to one vassal and water powers to another vassal.
Once vassals have been chosen the vassal can activate the household vassal powers as a swift action by reciting the command word chosen by their dungeon artifact holder.
If the household vassal's mana is exhausted their artifact holder may increase their vassal's mana pool by 1 by expending 1 point of their own mana pool as an immediate action.
If a household vassals benefactor has multiple dungeon artifacts, they must specify which they which to activate granting them the major vassal power of the artifact, however they will still gain the minor vassal powers for other dungeon artifacts their holder might have.
A character (NPC or Otherwise) can only be a household vassal for one dungeon artifact holder at a time. To change benefactors they must sever their link to the dungeon artifact holder by being released. Releasing a vassal prevents the vassal from being a vassal for a new benefactor for 24 hours per rank of the dungeon artifact they are linked to.
If household vassals get too far from their dungeon artifact holder the link automatically breaks. This distance is equal to 1 mile per rank of the dungeon artifact.
Temporary non-native outsiders cannot become household vessels as the dungeon artifact's link is anchored to the material plane. Thus it is impossible for a strong link to be connected to creatures from outside of the material plane.
Companions fused to the dungeon artifact holder (sythesized eidoleons, tumor familiars, etc) cannot be made household vessels since they share the benefit gained by activating the dungeon artifact itself as a holder.