Complex sentence: Black magic is the type of magic that draws on assumed malevolent powers and/or is used with the intention to kill, steal, injure, cause misfortune or destruction, or for personal gain without regard to harmful consequences.
Split into simpler sentences: Black magic is the belief of practices of magic that draws on assumed malevolent powers. This type of magic is invoked when wishing to kill, steal, injure, cause misfortune or destruction, or for personal gain without regard to harmful consequences.