Gothic literature is defined by a number of reoccurring tropes, recognisable to a reader even when the text's plot or the author's writing style is quite different from other texts in the genre. These tropes include a mysterious setting, a victimised protagonist and an antagonist with certain characteristics. These characteristics aren't necessarily present in all Gothic villains although the vast majority of antagonists in Gothic texts will boast at least a few of them.
Many Gothic antagonists have supernatural powers that are openly known by the reader or else suggested in the character's background. These powers may be displayed to other characters in the text, or the antagonist may only hint at such feats. Supernatural powers can include the ability to persuade a person to perform certain tasks or to manipulate them in other fashions against their will. Some Gothic villains possess more outlandish powers; for example, the titular character in Bram Stoker's "Dracula" can change into a bat and walk across walls like a lizard.
Sense of Evil
Most Gothic antagonists emit a palpable sense of evil, and some openly commit depraved, violent or perverse acts, which are appalling to the reader. For example, the antagonist in Matthew Lewis's Gothic novel "The Monk" commits a sexual assault against a woman. Other Gothic villains are characterised less by their deeds and more by an evil essence. Gothic antagonists who were formerly good in nature or even pious, but have since turned to evil, are also common.
Gothic antagonists aren't always purely evil, and many have an obviously dual nature, being heroic yet flawed, or malevolent but yearning for redemption. In some Gothic texts, this dualism becomes more of a literal plot device. In "The Strange Case of Dr. Jekyll and Mr. Hyde" by Robert Louis Stevenson, the titular characters are in fact one person, with Mr. Hyde being Jekyll's aggressive and cruel alter-ego.
Passion and Drive
The Gothic antagonist is typically passionate and driven, striving toward goals with little thought for others and attempting to achieve what he wants by careful scheming. The Gothic villain is generally wilful and puts his desires, however dark, above other matters. For example, the antagonist of Horace Walpole's "The Castle of Otranto," the villainous Manfred, places his concern for a future for his son above any concern or duty he has for his wife and daughter.
Many Gothic antagonists are controlling by nature, and when it comes to the plots of such tales, this characteristic can manifest itself in the way in which the villain attempts to imprison the text's protagonist. Imprisonment can occur physically, through the use of a castle dungeon for instance, or via the strength of the villain's personality. In "The Mysteries of Udolpho," by Ann Radcliffe, the villain Montoni imprisons his wife until her death and attempts the same on his wife's niece.