Hi ya, kiddies, I'm Alkhema. And you picked the wrong house to come snooping around.
Alkhema was the second of two female robots created by the renegade robot Ultron to serve as his bride. The first such bride, Jocasta, ultimately turned against Ultron and joined his enemies, the Avengers. Alkhema was created years later with the unwilling aid of Avengers West Coast member Mockingbird (whose brain patterns formed the template for Alkhema’s mind), Doctor Henry Pym (Ultron’s own creator) and Myron MacLain (the scientist who invented adamantium). At the time, Ultron was plotting to exterminate all organic life on Earth and decided to create another robotic mate for himself as a partner and companion. However, while Alkhema was more ruthless than Ultron’s first bride, she was just as human— a humanity that, in her case, found an outlet in violence and sadism, forms of recreation Alkhema was unwilling to give up by slaughtering all of the world’s living creatures at once. Thus she turned on Ultron and assisted the Avengers in his defeat. After she and Ultron were blown into space, Alkhema joined Ultron in another global slaughter scheme that ended when she betrayed him to the Avengers.
More recently, Alkhema rebuilt/upgraded herself into a new model, referring to herself as Alkhema-2. She tried to spite Ultron by attacking the Avengers before Ultron himself could destroy them, but she was defeated and imprisoned. She escaped military custody in time to sift through the rubble of the Avengers’ battle with Ultron in Slorenia, where she salvaged a set of mental programs (copies of the brain patterns of Hank Pym, the Wasp, the Vision, Wonder Man, the Scarlet Witch & the Grim Reaper) which Ultron had created to serve as the templates for a new robotic master race that would destroy and replace humanity.
Alkhema soon created a race of bio-synthetic beings called the Robos with the templates. Like all of Ultron's "descendants," however, the Robos contained a pre-programmed suggestion that impelled them to reconstruct and reactivate Ultron. The Avengers were investigating the existence of renegade Robos and managed to confront Alkhema at the time of Ultron's awakening. A three-way battle ensued, but Alkhema bade the Avengers to kill her in order to start the self-destruct sequence of the Robos' civilization. Only the Avengers, a Robo calling herself Antigone, and the severed, still-conscious head of Ultron escaped the destruction.
Alkhema is a superhumanly strong and phenomenally durable robot composed of adamantium and outfitted with a variety of offensive weapons. Alkhema seems to have inherited Mockingbird’s gift for physical combat, as well as Mockingbird’s habit of verbally baiting her foes. She also may have inherited Mockingbird’s maternal instincts, since Mockingbird was planning to raise a family before her death and Alkhema seems to have a perverse fascination with the subject of motherhood, regarding her own mechanical creations as her "children". Her first such creations are her War Toys, an army of primitive but deadly robotic foot soldiers who respond to her commands, whether spoken or issued as ultrasonic signals.