Nadziranim are evil wizards who practice the black arts of right-handed magic and serve the Darklords. They barely possessed individual personalities, rather they had something more like a collective mind of a colony of ants. They would obey instructions even if it meant their own demise.
They were created by the Dark God Naar and sent to Magnamund to conquer the world for evil. Presumably, they arrived in Magnamund with the Darklords in MS 3072. They are also the individuals who imbued Vonotar with the powers of right-handed magic, allowing him to become the greatest wizard of the age.