She was portrayed by Rachel House.
Rivalry with the Valkyrie
Serving as a bodyguard to Grandmaster alongside a fellow Valkyrie dubbed 142, Topaz has developed a certain rivalry with 142, even trying to convince the Grandmaster to reduce 142's reward to no avail. Despite this, Topaz seems to share the Grandmaster's desire of winning the people's hearts by using different life-forms in a gladiatorial event (known as the Contest of Champions) held in a large arena. She even helps the Grandmaster in intimidating his new fighter by handing him his melt-stick to execute another Sakaaran.
Following Thor and Loki's exile to Sakaar after being defeated by Hela, the Grandmaster had Thor captured while Loki wins the favor of becoming an ally. As the Grandmaster and Loki arrange a fight between Thor and the Hulk, the Grandmaster informs Thor that he will grant his freedom if he defeats the Hulk. Topaz watches as Thor almost defeats the Hulk, but the Grandmaster secretly sabotages the fight to ensure the Hulk's victory, as he has no intention in setting Thor free.
Eventually, Thor manages to escape from confinement and freed the Hulk from the Grandmaster's control by using a recording of Black Widow. Outraged by this, the Grandmaster orders the Sakaaran Guards to capture both Thor and the Hulk, but after reliving the deaths of her fellow Valkyries (thanks to Loki's magic), 142 decides to help Thor in defeating Hela and her army of Berserkers, since Hela was the one responsible for the massacre of the Valkyries. 142 even captured Loki to prove her goodwill, though Loki decides to ally himself with Thor to save the Asgardians from Hela's wrath.
When Thor, Hulk and 142 steal one of the Grandmaster's pleasure crafts in an attempt to flee, Topaz chases after them in her own fighter ship, intending to take them down under the Grandmaster's orders. Though it would've appeared that she seemed to have them on sight, the Hulk accidentally released the pleasure craft's fireworks, distracting Topaz and causing her to crash-land her ship to her death.