Severus Snape

At first, we learn about Severus Snape as a renowned Potions Master. He is clearly a gifted individual who is well aware of his abilities. As the plot unfolds through the novels, the fifth Harry Potter book reveals two other powers that this tormented professor has - Occlumency and Legilimens.

.

For those unfamiliar with the Harry Potter lexicon, when a wizard learns these abilities, he has the ability to shield his mind from external assaults. Most impressively, he can even enter the other person's mind and thoroughly read it. Moreover, the whole series demonstrates Severus's "enthusiasm" for the Dark Arts through his persistent attempts to receive the position of A Defense Against Dark Arts professor.

.

While J.K. Rowling depicted professor Snape as a ghost that hides in the dark, a strong embodiment of power, he is just a simple human at the end of the day – and an imperfect one at that. He is not entirely capable of expressing facial expressions, save when displaying revulsion at the appearance of Harry. Still he has very powerful emotions that help him to envision and eventually achieve his goals. This fact drew readers' attention to Severus Snape more than anything else.