Avada Kedavra

When you cast this unforgivable curse, you emit flashes of green light targeting one creature within range. On a hit, it causes the creature to die instantly. This spell can't be countered. Ignore all non-magical AC bonuses from armor and shields.

Unforgivable Curse effect: If casted, you lose "good" alignment and can never gain "good" alignment in the future. If you targeted a "good" or "neutral" aligned creature with this spell, your alignment changes to "evil" permanently.