The Red Queen
Even as a young child she was manipulative. When she first met the younger and gullible Chefwick, she immediately sized him as an easy mark, and used her feminine charms to hold Chefwick under her spell.
He was none the wiser about her true devious nature, always viewing her as the innocent Lucia. Years later, as adults, she could still sweet talk him into anything, helping her acquire by design, or by theft, more technology and greater riches. When he became the Mock Turtle, she used him as a more powerful tool to achieve ever more ambitious and equally evil goals.
She happened upon the set of abandoned Chessmen armor and conned Chefwick into restoring and enhancing the armor pieces capabilities. All the while, she was making outward moves into some of the other British crime lords territories, using with her own troops, the Red Queen's Men, as persuasive and sometimes deadly musclemen.
A rival crime-lord, Clever Dick, went to Marty and convinced him (for a tidy sum), to help Dick achieve the upper hand in the turf wars. Poor Marty was still completely unaware of Lucia and that it was her, as the Red Queen, usurping the power of London's underworld. After he returned to Lucia from a crushing defeat, Lucia revealed her true nature to Marty.
Enraged at him for all her years of feigning kindness and to be re-payed by having her growing empire smashed by him unwittingly aiding her ally, she unleashed the Chessmen to kill Chefwick.
They chased him throughout England, even crossing the Atlantic Ocean, and finally catching up with him as he approachedAstro City. With the aide of Steeljack and dozens of minor "black masks" living in Kiefer Square, Chefwick witnessed the defeat the Queen's henchmen.
Her attire and name, like the Mock Turtle's come from Lewis Carroll's from Alice in Wonderland. Their design is influenced by John Tenniel's drawings.
The fate of the Red Queen is never explained. Perhaps she found ways to manipulate others and regain another foothold in the London crime world. Or given the damages done to her financially and organizationally, it prevented her from regrouping and rebuilding her evil empire. Given her hot-headed and toxic emotional characteristics, she probably dwindled into an self-agonizing, contemptibly-bitter and very angry old nag.