A silvery substance extruded by certain stones in regions of Ysgard and Karasuthra, moonblood is used as warpaint by celestials as a result of its natural properties at enhancing defense and fending off natives of the Lower Planes.
Applying moonblood properly requires a DC 22 Craft (painting) check; when successfully applied, moonblood provides its wearer a +2 sacred bonus to AC for one day. After one day, moonblood is absorbed harmlessly by the skin of its wearer. Evil beings that touch moonblood take 1d6 damage per round of contact.
- Book of Exalted Deeds, pg.38