Godwin is the chief of public maintenance for Neo Domino City and the leader of Yliaster, a group that started with the ancient Andes people and today governs all things controlling society. He claims to want to summon the Crimson Dragon to bring peace to the world, though some express suspicion of his goals. For this, he takes Jack in as his protegé and uses the Fortune Cup to find the Signers.
Godwin is the technical definition of the anti-hero: one who carries out a just cause through any means necessary. He molded Neo Domino City into its current hierarchal society, in which Satellite residents are considered as scum. He is not above sacrificing them if necessary. He also makes sure to maintain total control of the Fortune Cup, such as when he arranges a consolation duel to reveal Luka as a Signer after discovering that Lua was substituting for her in the tournament. All this, though, is to awaken the powers of the Signers to prepare them for their upcoming fate.
After the Fortune Cup, Rex reveals the truth to Yusei that everything up until then was to prepare the Signers for the coming battle against the Dark Signers. He tells the legend of how the People of the Stars borrowed the power of the Crimson Dragon's five servants in order to seal the Nazca Gods, and since then the Signers and Dark Signers have been waging war constantly. Rex also discloses that the reason the Nazca Gods awoke in present day was because of a Momentum experiment 17 years prior, named Zero Reverse, where a cataclysm of negative energy caused the split between Neo Domino City and Satellite.
Rex has a mechanical left arm, revealed during the Fortune Cup when he caught Bommer's spike aiming to kill him. This fact plus a scene where Rex possesses a severed left arm with a dragon birthmark in a preservation tank hints at the possibility of Rex being the 5th Signer, though whether the arm really is his or not is unknown.
It is revealed in Carly's investigation of Arcadia Movement that Rex was actually born in Satellite.