Kace

"There are all kinds of leaders in this world. Each has a line they're willing to cross, a level of destruction they're willing to inflict to see their version of justice come to light. It's possible that Kace's followers once believed that the line he was willing to cross stopped at the lives of omnics. It doesn't."

- Tracer

Kace is an omnic leader who distrusts humans. He leads a gang, based out of the Underworld, and styles himself as a religious figure.

Story
"We have the parts, and I have a safe way to get them. My friend&mdash; A promise from the human? She said she was going to get us the parts. And what did she bring today? Human music. How will that help us in the next blackout?"

- Iggy and Kace discuss the former's friendship with Tracer

Inside the Underworld, Kace and his gang confronted Iggy, who had brought a human, Lena Oxton, into her quarters. Kace already disliked Iggy due to her interest in human culture (especially music), and the tension increased when Oxton returned, interrupting the confrontation. Kace refused to greet Oxton, and warned Iggy that humans knew nothing of honor, before departing with his gang.

That night, Kace and his gang once again confronted Iggy. Oxton was bringing in parts to help fix the Underworld's grid. Kace, sneering, asked what good music would do. As if on cue, the grid gave out. Kace warned Iggy that while omnics fought for the whole, humans only looked out for themselves, and that she'd soon see the truth. He led his gang out of the Underworld, intent on stealing the parts required to fix the grid, since under UK law, they could not be sold to omnics legally.

The next night, Tekhartha Mondatta was assassinated, while giving a speech in King's Row preaching human-omnic unity. The assassination sent shockwaves throughout London's omnic community. Kace, rallying the Underworld's omnics to his side, declared that Mondatta's message of peace was over. Now was the time for war.

Kace began rallying the omnics of the Underworld to his side, arguing that it was time to strike back. He took part in a protest against the police that resulted in the deployment of Special Ops. They brought out a sonic pulse device; Kace yelled to "destroy the machine," while many of the protesters began to flee. In the ensuing chaos, an omnic, Lady, was killed. Kace attended the funeral, as did Tracer. Afterwards, he confronted her, accusing her of fighting for Overwatch in order to kill omnics, harkening back to the King's Row Uprising. Tracer claimed that she fought for freedom, but Kace wasn't listening. She'd clearly chosen her side, and he ordered her to leave the Underworld, telling her that she wasn't welcome. She obliged.

Kace conducted another rally, claiming that humans would invade the Underworld. That tonight, we would rise. Some omnics sided with his call for action, others stating that they should focus on repairing the grid. During the speech, a sniper fired at Kace, the bullet grazing off his face. He extolled the omnics to search for the assassin. In truth, however, one of his own followers had fired at him as a false flag, in order to garner sympathy. The omnics scattered, but as Kace 'limped' from the stage, he was confronted by Iggy, who correctly deduced that the assassination attempt was a ploy. She told him that he wanted to be like Mondatta, but that he was no leader.

Kace took Iggy prisoner, before he was confronted by Tracer and Lizzy. One of his thugs held Iggy from a great height, ready to drop her. Kace told Tracer that the revolution was nigh, and that there was nothing she could do to stop it.

Kace's followers opened fire on Tracer and Iggy. His henchman dropped Iggy, but Tracer, using her super-speed, was able to save her. They escaped, but his followers clamped down on the Underworld, rounding up every omnic they could find, in order to force them to fight for him. He laid out his plan to detonate the grid once human forces entered the Underworld. Some were afraid of this course of action, but Kace dismissed their concerns, stating that the backup generator would cover their immediate needs. The detonation of the grid would nullify the humans' defenses. He similarly held no concern for the omnics still in the Underworld, stating that any omnics that hadn't joined his ranks would be a sacrifice for their victory.

Kace and his followers prepared to detonate the grid. However, Iggy's voice came out over the sound system, extolling Kace's followers to stand down. That violence would only beget violence, and that their aims would be achieved through peaceful means. To Kace's fury, his followers dropped his weapons. He drew out his pistol, and shot at Iggy, only for Tracer to take the bullet. He was forced to flee as his own followers turned on him.

Over the next week, Winston tried to find out what he could on Kace. He suspected that he might be tied to Null Sector.