Nora Fries

Nora Fries is the beloved wife of the Batman supervillain Mr. Freeze and serves as the central motivation for her husbands criminal activities. Nora suffered from terminal illness and was cryogenically frozen until Freeze could develop a cure. Although she is eventually cured of her condition in the mainstream comic continuity, she becomes a supervillain herself in both depictions of the event.

Post-Crisis
Nora was a gentle girl who first met Victor Fries during boarding school and would eventually marry him before becoming terminally ill from a fatal disease. Unable to bare the thought of losing Nora, Victor cryogenically froze her at Gothcorp until he could develop a cure to her sickness. His pursuits to do this led to the incident that transformed Victor into the supervillain Mr. Freeze and he began a criminal career to help further his research into saving Nora.

As time passed, Nora remained in cryostasis as bits of her frozen body occasionally broke off and were reattached, until Victor made a deal with Nyssa Raatko to build a weapon for the Society of Assassins in exchange for allowing him to revive his wife using the Lazarus Pit. However, when Batgirl convinced Freeze that Nyssa was not going to fulfil her part of the deal, he decided to put Nora into the pit himself.

A part of the pits alchemy seeped through the cracks in Nora's frozen body, which gave her the ability to summon the undead and conjure flames, but also drove her insane. Nora soon emerges from the pit blaming Victor for what has become of her, before taking the name Lazara and attacking everyone present with an undead army at her command. Freeze tries to reason with Nora by trying to remind her of the good woman she was. But Nora continues her assault, calming the person that she was is gone, which forces Victor to freeze her once again.

New 52
Nora's history was altered for the New 52. In this continuity, Nora's birth name is Nora Fields, who was cryogenically frozen at Wayne Industries in hopes of finding a cure to her terminal illness. Many years later, a scientist named Victor Fries became obsessed with Nora and came under the delusion that she was his wife and was determined to cure her. Despite Fries' dedication, Wayne Industries CEO Bruce Wayne tried to stop his research due to Vectors delusions which soon resulted in the creation of Mr. Freeze who continues to pursue Nora Fields.

Eventually Nora's history is again altered by the events of DC Rebirth, which combines elements from her two previous origin stories. Nora is again Victors wife but she is still frozen at Wayne Industries and Bruce Wayne still tried to stop her husbands research.