Rudger is the leader of the Dark Signer, bearing the Spider Birthmark resembling the Nazca Line. His Earthbound God is known as Uru, the strongest of the set. He holds the power to send spiders out and possess civilians - previously displayed over Dick Pitt and Ushio. His deck consists of a spider theme to suit his Earthbound God.
He is later revealed to be Rex Godwin’s elder brother and once an assistant to Professor Fudo - Yusei’s father. He was placed in charge of Old Momentum when Yusei’s father attempted to end the project and claims to have deliberately caused the Zero Reverse accident that killed himself and both of Yusei’s parents. He sets his targets on Yusei, even attempting to send Bommer after him once he was made into a Dark Signer.
In Episode 57, it's revealed that that he is, indeed, the long missing Fifth Signer bearing the Head Birthmark. The arm - in the possession of Godwin - was once his which has been replaced with an artificial replica just as his brother’s. He visited the Nazca Lines and met a man claiming to be from Yliaster. Once he returned, he was driven mad by the negative Momentum and took over MIDS, forcing Professor Fudo to flee with the Dragon cards - losing Ancient Fairy Dragons. Rudger then severed his left arm, with the Birthmark, and handed them to Godwin, pleading that it be taken somewhere safe and that he gather the Signers before he loses himself completely to the battle of gods inside of him - the Signer and Dark Signer born inside of his soul. Godwin did so and Rudger sent the Momentum into a reversal, creating what is later known as Zero Reverse, splitting Satellite from Neo-Domino. He was killed in the process and revived as a Dark Signer as he wished in his last moments - the leader bearing the Spider Birthmark.
After explaining everything to Yusei, he fights until Yusei is standing over the brink of death, only for the Signer to fight back and destroy his Earthbound God, ending the duel.
Rudger laughs and claims that an "Underworld King" will be unleashed if the towers aren't sealed by sunset. Yusei asks what he means, but Rudger answers that he won't allow Yusei to leave Old Momentum and detonates his artifical arm, destroying the bridge they stand on and sending Yusei plummeting into the Momentum beneath - what he claims is the gateway to Hell that he discovered alongside Yusei's father 17 years before.
Once the Signer War is over, he and Godwin reveal to Yusei they've learned the error of their ways and move on to the Afterlife with the gift of reviving the Dark Signers to the world of the living.
