Kari Limbo was an psychic entertainer at a circus when she met Guy Gardener before he became a Green Lantern. The two of them fell deeply in love. In the midst of their romance, Hal Jordan decided to leave Earth and asked Guy to take his place while he was gone. Hal was unaware that his power batter had been sabotaged, and the battery exploded the first time Guy tried to charge the ring. Kari, Hal, and the rest of the world all assumed Guy had died in the explosion.
Hal comforted Kari over the loss of Guy. Though Kari's grief led her to blame Hal at first for everything that had happened, the two eventually fell in love and, after some time passed, they decided to get married. Unfortunately, Guy was not dead - the explosion had sent Guy to the Phantom Zone and he could see everything that was happening outside of it. Just before the wedding, Guy managed to reach out to Kari telepathically, leading Kari to realize that Guy was still alive and to call off the wedding. Hal went to rescue Guy, resulting in Guy being alive but comatose.
Kari felt that she couldn't marry Hal if Guy was alive, but when Guy came out of his coma he felt too hurt and betrayed to renew their relationship. Hal and Guy both moved on and Kari was left alone.
During Zero Hour, it was revealed that Kari Limbo died with the other residents of Coast City when Mongul and Cyborg Superman destroyed it. During Underworld Unleashed, Neron tried to temp Guy Gardner with bringing Kari back from the dead, alongside Kilowog, Ice, and Gardner's family. Gardner did not succumb to Neron's temptation.