The type of spells characteristic of Dark Arts are known as curses, which usually cause harm to the target. All, to a certain degree, are in some circumstances justifiable. The motivation of the caster affects a curse's result. This is most notable in the case of "Cruciatus": when cast by Harry, angered by the death of his godfather at Bellatrix's hands and desiring to punish her, it causes a short moment of pain. As Bellatrix herself comments, righteous anger does not allow the spell to work for long. When cast by figures such as Voldemort, who desire to inflict pain for its own sake, it causes intense agony that can last as long as the Dark witch or wizard desires. Use of Dark Magic can corrupt the soul and body; Voldemort has used such magic in his quest to prolong his life and obtain great power. The Dark Arts also cause Voldemort to look deformed and inhuman, a side effect of splitting his soul into Horcruxes.