Necrosius

Necrosius the Undying is a former Death Guard Apothecary turned sorcerer who drew the first Apostles of Contagion out of the Legion. The Apostles are plague preachers who spread the doctrine of Nurgle among the followers of Chaos and the servants of the Imperium alike.

Necrosius abandoned his medical duties after Nurgle’s influence reached the Legion’s fleet, which rendered the Apothecary’s task of preserving life futile. He set aside the narthecium, the Apothecary’s instrument for gathering gene-seed and treating the wounded, and took up sorcery. Imperial agents and the sorcerer Ahriman have each been reported to have killed him, yet he has repeatedly reappeared, a record that accounts for his epithet. At Vraks he raised a host of zombies and employed the dead as a renewable labour force.

Necrosius is not comparable in standing to Typhus, and his role is of a different kind. He is regarded as the origin of the Apostles of Contagion, an organised body of preachers within the Death Guard’s wider following. That body continues to operate, and it carries the Legion’s devotion to Nurgle into regions beyond the Legion’s own fleets.