Dr. Belinsky was brought to the lab complex of Sergei Krylov, alias the "Presence", a scientific genius who had become one of the most influential men behind the scenes of the Soviet government. Sergei mentally dominated Tania, and used a Chernobyl-like nuclear disaster to transform Tania into his super-powered thrall with nuclear powers. She battled the Defenders alongside the Presence, and then separated from him. She was later assigned to investigate the Presence's reappearance, and after battling a giant amoeba, she reunited with the Presence. Alongside the Presence, she encountered the Hulk, Darkstar, Crimson Dynamo, Vanguard, Ursa Major, and Professor Phobos. She and the Presence left Earth since their radiation levels were too dangerous for them to remain. Tania and Sergei were eventually revealed to be laboratory subjects on one of the Stranger's laboratory worlds. After regaining their freedom, Tania took the name Starlight, and returned to Earth with the Presence and Jack of Hearts. She battled Quasar and the Fantastic Four, and aided the Presence in his attempt to kill Eon, though she ultimately admitted only doing so because the Presence (the only person who could safely remain around her due to him making her radioactive) threatened to abandon her if she did not serve as his henchwoman and lover. She was later seen battling Darkstar and the Black Widow.