The Unforgivable curses are made up of 3 spells. The Cruciatus Curse, the Imperius Curse, and the Killing Curse. The Imperius Curse controls the person who it is cast at. Complete control. You can make a person do anything, both good and bad. The Imperius Curse gave the Ministry lots of trouble a few years back.. Many witches and wizards were being controlled by the curse. Some job, trying to figure out who was acting on their own free will or being forced to. The Cruciatus Curse is a curse that inflicts a tremendous amount of pain to the person on its reseiving end. You don't need knifes or skrews to torture somebody. The Cruciatus Curse was popular once too. The Killing Curse does just what the name implies. It kills, leaving no mark. Only one person has survived it, and they did it twice. There is no countercurse. No blocking it. It takes a powerful bit of magic to work. I'm going to write the incantaations down, but please don't use them. Using them on another human being will give you a one way ticket to Azkaban. The Imperius Curse: IMPERIO. The Cruciatus Curse: CRUCIO. The Killing Curse: AVADA KEDAVRA. I repeat, NEVER use these spells, NEVER!!