Nickel was born from a hotspot in Prion, one of the Titans who left Cybertron in its ancient past, searching for planets to colonize. Sometime eons later, the Black Block Consortia came to Prion and wiped out the entire population of mechanical beings... or so they thought. Nickel was the lone survivor of the genocide, and when the Decepticon Justice Division came across the scene and Nickel, she found the Decepticons' promise of organic genocide appealing. Subsequently, she came to work for the D.J.D. as a medic and something of a surrogate "mother", telling them off for neglecting their hygiene and maintenance, and endearing herself to the crew.
Following the D.J.D.'s punishment of Blip, they learned of Megatron's abandonment of the Decepticon cause and that he had joined the Autobots. At first, Tarn attempted to take his own life by overdosing on Nuke, but seeing Nickel's worried face as he neared death made him reconsider. She then accompanied the D.J.D. when Tarn courted Deathsaurus and his troops for a single purpose—war against Megatron, the traitor.
After their alliance stranded Megatron and his "sympathizers" on Necroworld, Nickel sat in on a strategy meeting with Tarn, Deathsaurus, Tesarus, and Vos. They were interrupted when Tarn left to take a call. He returned with Overlord in tow, who immediately set about mocking Tarn, suggesting that he made alliances because he was a coward. To Overlord's face, Nickel told Tarn to ignore the Phase Sixer. Kaon then rushed in, full of concern for The Pet. Tarn ripped his head off for his compassion, horrifying the tiny femme. Still, she marched out with him and the rest of the DJD-Deathsaurus alliance as sunset approached, preparing to assault the Necrobot's fortress.
During the battle, she used Vos in rifle mode to shoot Chromedome in the shoulder. As he'd temporarily become a superpowered outlier, they didn't really hurt him. When Megatron himself emerged, she ordered Helex and Tesarus to pull back under Tarn's authority and used Vos to disable the Autobot's fusion cannon, effectively neutering him.
To her utter dismay though, Tarn had ordered all their men to run at Megatron to wear him down. When Deathsaurus had an attack of conscience, Nickel decided they should all just pack up and go home. Tarn's obsessions, she realized, had always meant more to him than the Decepticon cause, and she departed with Deathsaurus and his remaining crew.