Adds a necromancer escort.
Saving it may teach Necrosis category, Blurred Mortality, Runeskin, or +5 magic/willpower.
Betraying it may teach Fungus category, Wild Growth, Ancestral Life, or +5 willpower/cunning.
Letting it die... well, one less corpse-wrangling madman in the world.
Thanks to nsrr for adding proper structure and betrayal rewards!