The Blasting Curse is a spell that causes anything that the spell comes into contact with to explode. A possible lesser version of it might be the Blasting Charm. The incantation is Confringo.
Effect: Confringo is a viral fire spell. It will attempt to deal fire damage to the target, and then try to jump to a nearby enemy, and repeat the process up to 3 times. This spell can affect as many as 30 enemies if they are close enough, and fail their saves. Each jump, has the chance to re-damage enemies already afflicted.