To tell the truth, when you read a novel, you always wait anxiously for the appearance of the main villain. Yes, because in a story, the villain is always the most fascinating and the most striking, and is often the one who gives adrenaline in a otherwise dejected novel.
My choice of characters would be:
Mamba Samba - A man whose grin will be the sign of the most terrible misfortunes, and whose presence would generate mysterious shivers of terror through the spine.
Lord Dang - A character that would have in him ambiguity, coldness, ruthlessness, pragmatism, craziness and lack of scruples to give the proper tension and adrenaline rush. It would take the form of what his victims fear the most.
Lady Daayan - A terrifying polygenesis with a character of great wickedness with the absolute evil in her. The character would go from being playful and almost sympathetic to a stealer of children, on which it would feed.