Ariadne Pixnit is an avant-garde tattoo artist who used "nanite-ink," a nanobot-filled color matrix that she could program to form itself into different designs, in her work as an artist. After being beaten and raped by a street gang, Pixnit works undercover at her attackers' favorite tattoo shop, designing lethal tattoos (swords, scorpions, etc) that she brings to "life" via remote-computer- control in order to dispatch the gang members one by one. She later injects a large amount of the nan-ink into her skull, giving her the ability to create creatures and weapons on her skin that she could animate and use offensively.
She encountered Batman and Bane when the two were in a temporary truce and working together. She had been hunting down and murdering her attackers, drawing the Dark Knight's attention. After a brief fight, Batman was knocked from a rooftop and she escaped while Bane saved him.
Later, she is shown to be tracking down the last of her attackers, and Bane has found her. After expressing relief at having attained vengeance, she and Bane embrace, having shared a sense of lost innocence. It is implied they parted as friends.