Holy water

Holy water is water that has been blessed by a priest of a - presumably - Christian denomination. Holy water is used as a weapon by vampire hunters. Holy water burns vampires like acid - it is also effective against half-vampires. Holy water is quite rare, as it is difficult to create - only a person with true faith in its power can create holy water that is actually harmful to vampires. Most holy water is not 'genuine' holy water and is ineffectual against vampires - to the point where many vampires don't even believe holy water works. The vampire hunters of Black Cross keep holy water in water guns to spray on vampires. There is also an uncommon practice of soaking stakes in holy water - being stabbed with one of these stakes cause intense and permanent pain to vampires.