Primeval

Primevals are a broad classification of creatures that are a fusion of 2 (or potentially more) of the 25 identified Elements of The World. They do not seem to age and apparently replenish if destroyed unless dispatched properly. Rígan Diavall identified the method as the use of Direct Opposition magics, applying spells that block the elements that compose them or that are opposite to the elemental nature that creates them.

Upon destruction they dissolve rapidly but do leave behind traces such as their hearts. It is highly recommended one not interact with the heart physically as it can flow into a body and take residence there. Neb was inhabited by the heart of "The Curlew" and sought healing in private with his comrades in the Household. Safiya later said that the effect had been resolved.