Caiera was one of the Shadow People, an extraterrestrial race who helped colonize the planet Sakaar. The Shadow People are linked to a primordial power that enables them to tap into the planet for additional strength. The Elders among the Shadows who raised Caiera recognized the Old Power in her and began her training. When she was 13, the extraterrestrial parasites called the Spikes overran her village, consuming her family and many others. Caiera was saved by Prince Angmo II of the imperial peoples, who planted an obedience disk into her so that she would be forced to serve him. Caiera eventually grew to become a lieutenant in the imperial Guard. When Angmo II succeeded to the imperial throne as the Red King, he made Caiera his Warbound Shadow, honoring the treaties between his people and the Shadow elders.
After 30 years of serving the Red King, Caiera met a formidable opponent when the Green Scar was brought to Sakaar by the meddling Shadow Elders, who hoped to fulfill their peoples' prophecies of the messianic Sakaarson by forcibly drawing such a person to their world. Enslaved as a gladiator, the Hulk emerged victorious in combat, but the Red King and Caiera personally defeated him when tried to fight them. As the Hulk became a famous personality on Sakaar through his gladiatorial victories, Caiera attempted to by him off by offering him a chance to retire in peace, but the Hulk refused her offer. Caiera helped arrange for the imprisoned Silver Savage to be pitted against the Hulk, but the Hulk won the fight, destroying the obedience disc in the process. Caiera then demanded that Hulk and fellow Warbound gladiators kill imprisoned enemies of the Red King, but they refused, and the Surfer ultimately neutralized the gladiators' obedience disc, making the Hulk a rebel leader.
Caiera led forces in attempts to defeat the Hulk's army, but when she finally faced him in personal combat, the Red King interfered by releasing Spikes into the area. Caiera helped the Hulk fight the Spikes and tried to obtain the Red Kings aid in protecting the village of An-Sara, but instead the Red king dropped deathfire bombs on the village. Caiera survived the bombing and the Red King's disregard for his own subjects' lives convinced her to switch her allegiance and join the Hulk's Warbound. Caiera aided the Warbound in combating the Red King's forces, and the emperor was finally slain.
The Hulk was named successor to the throne by popular acclaim, and he chose Caiera as his queen. Before they were wed, she had him reveal his greatest secret to her. He revealed his other identity of Bruce Banner, and she loved Banner as well as the Hulk. Caiera became pregnant with the Hulk's child, and they hoped to usher in a new age of cooperation among the many people of Sakaar; however, when the SHIELD vessel which brought the Hulk to Sakaar suddenly exploded, Caiera was caught in the blast, which destroyed Crown City. She died in the Hulk's arms, and her body was consumed by the planet's erupting lava. With Caiera's passing was transferred to Hiroim the Shamed of the Hulk's Warbound.