A necromagic spell made primarily of dark-ash and bloodpowder that causes the skin to "crack" and bleed out of the cracks. It's normally used as a means of torture, as it creates immense itching and pain, but can also be used to help dissolving a dead body for use in other spells.
A stronger variation of cracklebleed, known as shatterbleed, goes beyond the skin and tears the whole flesh apart, resulting in multiple small chunks of dried flesh once the spell ends.