The methods by which Department H found and recruited Lillian into Gamma Flight are unknown. She had a brief affair with Madison Jeffries after meeting him there, but the two would develop stronger feelings later.
Delphine Courtney recruited Lillian for Omega Flight using a mind control device. Madison returned to destroy Delphine while Shaman kept Lil distracted with illusions.
Lillian was pardoned for her actions as part of Omega Flight. She was angry at Jeffries' closeness to Heather Hudson, while Heather was angry at her for being part of the group that was responsible for her husband James' death. Guardian subsequently returned years later; Heather and Lil seem to have set aside their differences.
Lillian began secretly seeing Jeffries while he was engaged to Heather Hudson. The two reaffirmed their feelings while both were fighting Diablo.
Lillian had a breast cancer scare after feeling a lump while examining herself. This was especially difficult to deal with because her powers made normal removal impossible. While Alpha Flight battled aliens, she was harmed by a laser from one of them. She chased the being down, stole its laser, and asked Jeffries to modify it into a scalpel. She successfully underwent surgery; the lump was a benign cyst and she made a full recovery.
Madison and Lil married and agreed to retire from active duty. However, Madison continued to use his Box robot. She worried he had become addicted to adventuring.
When Alpha Flight reformed, Lillian was angry that Madison wanted to join the new team. They had a fight and parted ways. He came to the Department H headquarters in Toronto to join the team, while she went to take care of some personal stuff. Sometime later, Diamond Lil in full costume arrived at the headquarters building in search of her husband. Two members of Epsilon Flight arrived to escort her to the infirmary, where Madison was supposedly waiting for her. This was an obvious lie as Madison was at the time in the custody of the Zodiac.
Lil was captured by Dr. Horatio Huxley of Department K and experimented on. Thetagen-24 was injected into her system. While the previous subjects died, Lillian's powers kept it contained around her skin. Alpha Flight managed to rescue her. However, she did not rejoin the team.
Lillian was captured by Weapon X and sent to Neverland. She and Random resisted when the guards began separating prisoners into who was suitable for being made an agent and who was not. They were severely beaten by the Boxbot guards, their powers negated by a dampening field.
Lillian survived and retained her mutant powers during M-Day and was one of the mutants who sought refuge at the Xavier Institute during the chaos.
Following the Institute's destruction, the X-Men's relocation to San Francisco, and the X-Men's establishment of Utopia, Lillian made her way to the island nation. There, she sought out her husband, initially frustrated at him for not understanding her needs. Slowly remembering his inherent inability to understand people, she came to forgive him and the two made up. A day after they had made up, Selene's forces invaded Utopia, and in the chaos, Lillian was killed. Madison buried her at sea in a glass box he made, symbolizing how he could always see her, but never felt as if he could effectively touch her.
