“ | We are Sigma. Created by Tenjuro Banno, we are the deity that will oversee mankind. | „ |
~ Sigma introduces itself to Drive and Heart |
The Sigma Circular, also known more simply as Sigma, is a sentient machine created by Gold Drive and Roidmude 004 to dominate all of humanity and the final antagonist of Kamen Rider Drive.
Its function is to forcibly convert every human on Earth into data, assigning them a specific numerical designation in the process, allowing its operators to control who get physical bodies.
It was co-voiced by Ayumi Fujiwara and Masakazu Morita.
History[]
Sigma Circular was created by Banno to fulfill his desire to become a god by triggering a second Global Freeze and converting everyone on Earth into data. Once everyone was digitized, Banno could force the world to submit to him by only giving bodies to those who bowed down to him.
After being revived as Gold Drive and taking over the Roidmudes, Banno gathered the three Roidmude executives to perform the "Promised Number" in order to power Sigma up. To conceal his true intentions, Banno claimed that Sigma was simply a stabilizer meant to ensure the event went as safely as possible. Banno had originally intended to use Medic as a sacrificial vessel for the machine's countercurrent, but Brain took her place instead and gave up his own life in the process.
With Sigma activated, Gold Drive fled the scene and gathered the remaining members of Reaper Legion to infiltrate the Special Defense Center headquarters, where Banno intended to trigger a second "true" Global Freeze from. As Kamen Riders Drive, Mach and Chaser approached the building, Sigma generated spikes from the ground in an attempt to stop them, but the three were able to evade Sigma's attacks.
After breaking through the forcefield and getting inside the building, the three Riders were joined by Roidmudes Heart and Medic, the last of the 108 original Roidmudes. Soon after, Gold Drive then appeared to deal with them and Heart vowed to destroy Sigma Circular and thwart his ambitions. While Mach and Chaser stayed behind to deal with Banno, Drive, Heart and Medic went off to to shut down Banno.
Sigma's evolution was completed, activating the second Global Freeze just before Drive and Heart arrived to stop the machine. Though Gold Drive was destroyed and Banno was finished off by Go around this time, Sigma still attempted to continue its original directive by converting everyone into data. Initially, Drive and Heart were unable to damage the machine, which repelled them every time they tried to land an attack. Though Shinnosuke was injured, he was healed by a weakened Medic, enabling him to become Drive again. After Drive and Heart combined their powers to launch a final attack, Sigma was destroyed by the combined force of Drive Type Tridoron's Rider Kick and Heart Super Evolved's strength punch. With its destruction, the Global Freeze ended and all the humans who were transformed into data were returned to normal.