A half-robot witch Alejandra Villarreal with bright black hair, combining magical and mechanical features in her appearance. Her Halloween makeup is decorated with details of toads and small spiders, adding a spooky and mysterious touch. The atmosphere is gloomy and dark, with a triad color palette centered on purple, accompanied by complementary tones that create a perfect harmony and accentuate her sinister appearance. Her metallic skin reflects flashes of dim light, while wires and circuits intertwine with magical elements, giving her a futuristic witch aura on a Halloween night.