Necromancy

To call this sphere "common" would be inaccurate — it is more that the abilities that are classified within it generate enough fear and discomfort for their stories to spread wide. This category refers to powers to do with the dead.

The most widely rumoured ability would be the power to bring the dead back to the living, and this tale often involves cautions about what truly comes back — usually a shambling, cannibalistic shell of what the person used to be, a demon or an animalistic mockery of a human being inside the remains of a person. Other times, what comes back may have a more vampiric tale attached, crawling from the grave to feast on blood and flesh, with their own supernatural powers. Alternatively, perhaps someone can also be risen whole and sane from the dead, but with a cost attached.

Other abilities would be mediumship — the communication with spirits, to gain wisdom about their past lives and how they died. This is one of the more approachable facets of this power, and is occasionally classed as Clairvoyance.

Lastly, necromancers could have the power to be be merciful. They could send someone who is suffering a fatal wound or illness to a peaceful end, or even postpone and numb death until help can be found or, perhaps, for final tasks to be completed before they are sent on their way. Whether this latter concept counts as merciful depends entirely on the necromancer.

Ideas about necromancers can change for settlement to settlement. Some see them as the most cult-like and perverse of mages, others might regard them as spiritual beings who are protective over funeral rites and respect towards the dead — it is more likely that they are simply normal people as mages tend to be, as concrete evidence supporting anything stranger simply doesn't exist.