Her perfect, gentle image makes her seem like a lily of the valley, pure and delicate. But, like the flower, the sweetness is misleading, she hides a corrupt, selfish side. Beatrice is merciless as she shows no regret for the murder of her fiancé. She tries to manipulate her servant to get Alonzo murdered. She knows the power and the division there is between classes, thinking that the use of money will get De Flores to do whatever she wants him to. Rather than feel an ounce of repentance, she further manipulates, as we see in the case of Diaphanta sleeping with Alsemero. She would rather blame fate than reflect on her actions.
He’s a serpent wrapped around a dagger, quiet until he strikes, driven by obsession, and using his violence to carve out control over Beatrice. Consumed by desire and jealously, he is willing to murder and mutilate to get her attention. While everyone else is blinded by their appearances, he sees through everyone's masks and knows the truth about their motives. Though he is technically her servant, his obsession gives him power over Beatrice, forcing her to bend to his will. Unlike others, he owns every dark choice he makes.
Beneath the calm, rational exterior, he is infatuated with Beatrice. He can look past her for murder and deception but becomes obsessed with her sexual purity, even tests her virginity. He assumes the role as a moral center of the play, speaking truth and attempting to act rightly, but his mind is often directed by his desire and possessiveness. His reason is strong, but it shares space with obsession, showing a tension between his ideals and impulses.
Alonzo is naive, he doesn't catch on to Beatrice's dislike of him and too readily trusts DeFlores until this trust leads to his death. His crush on Beatrice means that he overlooks all the red flags. Making him a cautionary example that being rich and polite does not save you from deception. His death is thus sudden, shocking, and completely avoidable had he only been a bit more cautious.