This spell could be used on the caster or anyone they touched. Once cast, blood lightning was undetectable until the target of the spell bled. A remove curse spell could negate the spell if cast before blood lightning was activated.
Once they began to bleed from an injury, the target of this spell had ten minutes where they could either heal themselves a bit or lash out with the spell's energy. If released as an attack blood lightning appeared as a web of red lightning shooting from each of the caster's bleeding wounds. Any creature within a 40 ft (12 m) radius of the caster would suffer intense harm from the lightning attack. The caster was unable to protect anyone within striking distance from harm.