This version of Ravonna Renslayer is a divergence of the Ravonna of Earth-6311, a.k.a. Other-Earth. This Ravonna's history is the same as her mainstream counterpart up to her death at the hands of Baltag.
Ravonna Renslayer was the daughter of King Carelius, a ruler in the 40th Century's Earth. The kingdom of Carelius was the last bastion of civilization unconquered by Kang the Conqueror in that time period. Kang spared them because he was smitten with Ravonna and her fire. She refused his love because he was a commoner and not royalty, but he swore to win her heart eventually. Kang summoned the Avengers to his future in the hopes of winning Ravonna's affection by displaying his battle prowess. Instead, the Avengers joined forces with Ravonna when Kang grew tired of the games and ordered a full invasion of her kingdom. After Kang conquered the Avengers and the kingdom, he demanded a wedding ceremony be prepared. Kang's code had always been to kill the rulers of any conquered nation, however, to prevent uprisings. His general Baltag betrayed Kang in order to honor that code and tried to have his ruler assassinated. Kang ended up allied with Ravonna and the Avengers to stop his rebellious army. Baltag was defeated but tried to kill Kang with one last shot. Ravonna threw herself in the path of the blast, saving Kang's life. She professed her newfound love for him with her last breath.
After a battle against Thor, Kang the Conqueror was split in two different counterparts. The dubbed himself "Prime Kang" ended up in Limbo, at Castle Limbo. There, he found the Immortus' skeleton and, believing him dead, took control of Limbo.
With Immortus' technology, Kang plucked Ravonna away from the Timestream the moment before she was going to be killed by General Baltag, creating a divergent Ravonna (this version) and a divergent reality where he was killed instead of Ravonna.
After the Prime Kang killed his other two remaining counterparts, Immortus appeared and, after revealing he was the future and final counterpart of the Prime Kang, apparently killed him with a sphere containing the memories of all the divergents Kangs slain by the Council. After those events, Ravonna decided to stay with Immortus in Limbo.
After a lot of time spent together, Immortus and Ravonna became husband and wife; they adopted Marcus Kang, the son of a younger counterpart of Ravonna named Revelation and her timeline's Kang. Marcus, who considered Immortus and Ravonna his "parents", became known as Marcus Immortus.
One day, an aged Immortus was able to understand that he was slowly dying; since he wanted to die with his love Ravonna, he asked Marcus to bring at Castle Limbo several alternate versions of her: one of them was going to be selected to kill the old Ravonna in the same moment Immortus will die. The Ravonnas who were taken by Marcus included a Nebula-like Ravonna, the Terminatrix (the Ravonna from Earth-6311), a Grandmaster-like Ravonna, a classic Princess Ravonna, a Kang-like Ravonna and finally a Temptress-like Ravonna. At the death of Lord Immortus, Terminatrix killed the old Ravonna, who died with her love.