Renowned indie actress Gugu Mbatha-Raw (perhaps best known in fandom circles as Kelly in the Black Mirror episode "San Junipero") was announced as the female lead of the Marvel Disney+ series Loki last year, but her character wasn't confirmed until recently. She plays Judge Renslayer, an employee of the Time Variance Authority. Ravonna Renslayer has been a character in the comics since 1965, but how much of her original history will translate to the Marvel Cinematic Universe remains to be seen.
Ravonna has never been involved with or integrally present in stories adjacent to the TVA in the comics, but reframing her in Loki as a judge for the organization makes sense: alternate timelines factor heavily into her history. Ravonna hails from Earth-6311, also called "Other Earth," a parallel version of Earth where humanity made great technological advances during the Dark Ages. Humans established a colony called Luna on the moon, and this colony went to war with Other Earth. Other Earth later exploded the moon, causing the pieces to collide with and devastate the planet. The world was eventually saved by dimensional-traveling members of the Richards family.
Ravonna -- formerly Princess Ravonna Lexus Renslayer -- was the only known daughter of King Carelius, a monarch whose kingdom was the last on this Earth to be taken by Kang the Conqueror. When he sent Ravonna to speak with Kang, she stubbornly refused to cede the kingdom and swore that they'd fight to the death for their freedom. This impressed Kang, who spared them because of his growing affection for Ravonna.
Two years later, Kang returned to their kingdom, this time offering to spare the kingdom in exchange for Ravonna's hand in marriage. She refused him -- he was a commoner and he was also, well, a conqueror -- but he persisted, allowing her father to remain the ceremonial ruler of the kingdom even though he was the one in true control, simply because he wanted to have a chance to win Ravonna's heart.
Eventually Kang invited the Avengers to fight him, hoping to either defeat them or get them to submit to him in an effort to impress Ravonna. They refused this and instead aligned with Ravonna (who had again refused Kang's hand in marriage) to protect the kingdom from Kang's subsequent wrath, though their resistance was soon overcome by Kang and his armies.
He once again declared his intention to marry Ravonna, this time as an act of conquest, but Baltag, a member of his guard, pointed out that Ravonna should be executed, being a member of the conquered royal line who could rise up in the future. Kang decided against it because he desired Ravonna so intently, but Baltag took the opportunity to rebel against him. After Kang, the Avengers and free people of the kingdom fought back against these rebels, Baltag attempted to shoot and kill Kang, but an impressed Ravonna intercepted the blast, declaring that she did, in fact, love Kang.
For a while, she was kept in stasis and Kang periodically mourned her. He made a deal with the Grandmaster to get the power of life and death, but due to a snafu in the contest of champions, he had to choose which he wanted to control; he chose defeating the Avengers over reviving Ravonna. When the Grandmaster independently revived Ravonna and informed her of this, she swore vengeance against Kang.
She then disguised herself as Nebula and dealt with many obstacles, including the Council of Cross-Time Kangs, Doctor Druid, the Fantastic Four and being stuck in a timestorm, before taking on the title of the Terminatrix and fighting Kang directly. He sacrificed himself in the fight and she took the throne in Chronopolis before reviving him, killing him and reviving him again so they could live and rule together. She was allegedly killed during the destruction of Chronopolis.
Though she was competent, intelligent, skilled in combat, adept with weapons and technology and in possession of high-tech armor that allowed her to shapeshift, Ravonna often played the damsel role in the comics. She sacrificed herself because she'd suddenly decided to love the man who'd essentially stalked her. Even worse, her in-stasis body was a reminder of Kang's failures and he used her loss as an excuse for poor behavior.
Kang will appear in Ant-Man and the Wasp: Quantumania, played by Jonathan Majors, but whether or not his history will be tied to Ravonna's is unclear. Regardless, making Ravonna a TVA judge in Loki means that she'll almost certainly have more narrative agency and opportunity to develop as a character in the MCU.
Loki stars Tom Hiddleston as Loki, Owen Wilson as Mobius M. Mobius, Gugu Mbatha-Raw as Ravonna Lexus Renslayer, Wunmi Mosaku as Hunter B-15 and Sophia Di Martino, Richard E. Grant, Sasha Lane and Eugene Cordero in undisclosed roles. New episodes air Wednesdays on Disney+.