What are some literary villains that are very compelling without

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What are some literary villains that are very compelling without necessarily being complex?

Pic related. [Spoiler]The sheer depths of her lunacy and rage, and the tension as to whether or not she was actually going to commit the horrible murders made Medea extremely enjoyable. Her character didn't really develop, and the only facets of her personality are her immutable jealousy and anger, but she still really drove the story forward.[/Spoiler]

Made me wonder if villains can be driven solely by a constant emotion or mental state throughout the novel more easily than heroes can. I mean, villains are often motivated by extreme feelings of anger/jealousy/revenge, and allowing one's feelings to take control is seen as a villainous trait in modern society. Perhaps heroes that are driven by one or two primal emotions are more difficult to write well, not necessarily because they are one-dimensional, but because there would be a cognitive dissonance with cultural ideas of keeping one's emotions in check.