Beltyn's burning blood

Beltyn's burning blood was a necromancy spell that caused blood flowing out of open wounds to become corrosive.

Effects
The target of this spell was one creature that had open, bleeding wounds caused by an edged weapon or similar means (wounds from blunt weapons or those that had been dressed or healed did not produce enough blood). Alternatively, after the, the target could be uninjured, but the caster supplied the blood. The range of this spell was 10 yards (9.1 meters) per the caster's level or or more, and it did not require line of sight to the target. The target had to have blood (undead, elementals, plants, oozes, etc. were immune) and not be impervious to fire. The exposed blood was subtly and temporarily changed to become hot and corrosive to surrounding tissue. The burning lasted for some time, but the victim had several chances to resist before it ended.

Beltyn's burning blood could not be cast into the ethereal plane from the Prime Material Plane, but creatures that changed shape to hide wounds, or that melded with objects, such as trees or stones, could still be the target of this spell and suffer its effects.

Components
In addition to verbal and somatic components, this spell required as material components a pinch of saltpeter and blood, which could be that of a creature with open, bleeding wounds within range or a drop of blood in the caster's possession,  which they put the blood in their mouth and spat as they uttered the words of the spell.

History
The spell was created by, or at least attributed to, the early mage Beltyn. It was included in the Book of Bats some time before the mid–12 century DR.

This spell was published in "Volo's Guide to All Things Magical" and became generally known to the magical community, albeit still rare, by 1358 DR.