Gaia is a version of Tara Markov from the Dark Multiverse. She was a member of the Teen Titans who operated under the alias Terra and was secretly a spy working for the villain Deathstroke. However, after having a discussion with Dick Grayson, Tara betrays Deathstroke so she can build her own future without assistance.
On an unspecified version of Earth in the Dark Multiverse, the Teen Titans gathered in Titans Tower to say farewell to Kid Flash, who had decided to leave the team. Dick Grayson also used this moment to announce his retirement as Robin, as Dick felt he needed to distance himself from the identity. But while he made his announcement, Dick noticed that his words seemed to resonate with his teammate Terra and afterwards stopped by her bedroom to talk about it. Tara admitted that she was curious about his choice to retire as Robin when his mentor Batman could have still had much to teach him. Dick told her that while he learnt a lot from Batman, he was only taught the skills to become Batman, which limited him in crafting his own destiny. He continued by saying she did not need to live in the shadow of her brother Geo-Force, unaware that she actually thinking about her boss Deathstroke.
Terra mulled over Dick Graysons words as she reported back to Deathstroke, who berated her for potentially putting their work at risk by allowing the protege to the World's Greatest Detective get into a personal conversation with her. Tara soon began to argue about Deathstroke's own methods which caused him to slap her for talking back to her superior. Infuriated, Tara responded by launching him outside their hideaway using her Geokinesis before putting an end to their partnership by decapitating him. She then returned to the hideaway looking for Deathstroke's butler Wintergreen, who attempts to ambush her with a gun. Terra burns his hand off and forces him to help her replicate the same experiment that gave Deathstroke his powers, believing if she could use ninety percent of the brain like he could, then she would be able gain access into the full extent of her own capabilities.
Wintergreen straps Terra to a number of devices Deathstroke had just in case he ever lost his powers and presses a button that sends a surge of energy through her. Tara then collapses to the ground for a moment before causing a tremor as she rose to her feet. Wintergreen was shocked that she was still conscious, as Deathstroke spent weeks in a coma before recovering. But Tara told him that Deathstroke was just a man who never lived up to his potential, while she was so much more in comparison. Later, Tara went back to Titans Tower where she announced to Raven and Changling that she has abandoned the alias Terra in favor of using the name Gaia instead, since it represents the Earth itself rather than just the planets terrain. She also admitted to them that she worked as a spy for Deathstroke which Raven previously suspected after sensing an evil within her.