It is unknown when or how Zero was able to isolate a group of potential slaves and trap them within a large enery bubble. Once he had achieved this, Zero appointed himself "emperor" of his new city and forced his residents to fight in violent gladiator-style games for their freedom - and lives.
After several years, Zero was informed that two lifeforms had been detected out by the dome wall. The leader ordered their capture and dumped the travelling Amy Rose and Tekno the Canary. By Zero's command, the two were made to face each other in a battle to the death. Tekno gained the upper hand and was forced to make a horrible decision - kill her best friend or allow every other slave to be murdered. Tekno appeared to choose to end Amy's life, but Zero did not free the slaves, instead sending Clawbeast to attack the other Mobian.Zero's day out was ruined when the energy dome dissipated thanks to (the still alive) Amy's actions in the control room. To make matters worse, Zero was savaged by Clawbeast when the animal was teleported to his seat by Tekno. Soon after, the law-enforcement of the city beyond the collapsed dome rushed in and arrested the visibly-distressed Zero, ending his reign of terror.
- Zero is a parody of Emperor Nero.