A team of super-skilled criminals roams a science-fiction Wild West, each with their own reason to hunt for the ultimate prize: the 12 Rings of the Dead, which can raise the dead and grant eternal life.

Somewhere in the desert lies the world's greatest treasure: the 12 Rings of the Dead, the only source of the mysterious substance Zombie Powder, which can raise the dead and grant eternal life. Into this world stalks Gamma Akutabi, a man with a metal arm and a six-foot chainsaw, cybernetically enhanced master of the legendary martial art . But it takes more than one man to find the ultimate prize. You need a team: super-gunman C.T. Smith, knife-slinging teenager Elwood, and brilliant (and impossibly big-breasted) journalist Wolfgangina. Against an army of crooks and killers, against runaway trains and superpowered madmen, they'll need all their skills...but the most dangerous thing in the west might be the Rings themselves... All volumes except the first also contain a bonus short story by Tite Kubo: Ultra Unholy Hearted Machine (vol. 2), Rune Master Urara (vol. 3), and Bad Shield United (vol. 4).

Elwood was a knife-thrower caught in a life of crime until he met Gamma Akutabi, class "S" criminal, a man with a six-foot chainsaw and a metal hand. Soon, Elwood is caught up in Gamma's quest for the most precious objects in the world, the Rings that might give new life to Elwood's sister...or make Gamma even harder to kill than he is already. But to get eternal life, they'll have to put their own lives on the line...and look down the barrel of the gun of the only man who is Gamma's equal...