Nothing happens to turn Maleficent evil. No back story is offered or hinted at to explain her malevolence—she has just simply always beenevil. Since she has no past, there are no grounds for any sympathy for her. In the logic of the fairy tale, she exists to define the complete opposite of the good characters, Aurora, Phillip, and the fairies. Therefore, her motivations never change. Her experience does not follow an arc or lead to change. She shows up wanting to do hurtful things, and she dies wanting to do hurtful things. Her character is drawn so ominously that there is never any question whose side the audience should be on. Solitary, angular, and horned, Maleficent speaks in a deep, theatrically harsh voice and deploys a bitter, jealous wit to ensure that she appears completely without the capability to love or to be loved.
The film bestows on her the skill of creative spell-casting in order to present challenges for the good characters to overcome. She proclaims death to Aurora, but Merryweather skillfully changes that to a deep sleep. She casts a forest of thorny branches in front of Prince Phillip after he escapes from her castle, but the good fairies equip him with the power to slice through it. Finally, her transformation into a giant dragon makes her so threatening, so unfairly dominant, that there’s no question she deserves death, right then and there.