The Killing Curse, most notably known as Avada Kedavra, is a powerful spell that inflicts instantaneous death to the victim. One cast ejects a bright green beam. When a victim is hit, this causes them to fling backward and ragdoll on the floor as their health is instantly reduced to zero.
This spell is well-known for its powerful and sinister effects, which is instantaneous death upon the victim. Despite its long incantation, it is an effective spell to use when dueling or finishing off an opponent.
The Killing Curse is one of the only two spells in the game that causes instantaneous death upon the victim, the other spell being Deletrius, a killing spell that causes the victim to aesthetically dissolve as they perish.