Spell (Earth 4), Potion

Necromancy; 5 Minutes
This spell will infect the recipient with a debilitating disease. The infection is not contagious, but renders a victim unable to be healed from any source. When affected by Healing (or any other effect which would otherwise heal them), they must call “No Effect”. Against undead, this spell will remove the effects of a Cure Disease spell.

First Aid may still be used to stabilize someone under this effect (and bring them from -1 to 0 Body Points as normal), though it will not remove the Disease effect itself.
“With Necromancy I Disease you.”