Reddosutā Shikaku (レッドスターの刺客Red Star Assassins) is a criminal organization that was created around the time when Machine and his family were still living together. Compared to Team Rocket, the Reddosutā Shikaku are ten times more dangerous, although, they didn't start out that way.
They started out as any other organization with ambitions, growing slowly, commanded by Pulse Emerald who wanted more out of life than what his family gave him, although he loved his family deeply. To grow in reputation and profit, the Reddosutā Shikaku would take job from families with barely any money as assassins for hire. They would eliminate the person for their client and then eliminate the entire family if they couldn't pay, which most of the time, they couldn't. They did this for awhile until they stumbled back onto Pulse's family, the Emerald's. Knowing that he couldn't bring himself to do the job for them, Pulse rejected the job. However, the organization didn't like Pulse's decision and went ahead with their hired assassination. Unfortunately, Pulse heard about this and went after them to stop them.
In the process of going after them, Pulse was killed in the process. The Reddosutā Shikaku went on to kill the man and then went back to kill the Emerald. Fortunately for them, Team Rocket attacked them right before they could do anything, wiping out most of their ranks. The only member left, took over the very essence of Pulse himself, and even took his name, becoming the new leader of the Assassins. This new "Pulse" stayed in hiding until the day he could destroy the Emerald family from inside out, and remade the Reddosutā Shikaku in his image.
A few years afterwards, when Machine was about ten, the Reddosutā Shikaku came back and attacked them. Machine's older brother, Ruby Emerald was able to intercept some of their ranks and defeat them after he achieved the title Pokemon Champion and was returning home. Ruby, unfortunately, was only able to stop some of them while the rest attacked and was able to kill Machine's mother and "father". Ruby, to help Machine and his little sister, Sapphire Emerald escape, he called upon the help of the Dragons, a covert organization that were created in order to destroy the Red Star Assassins. One of their members, Lance, came to rescue them right before the Assassins were about to destroy them all, holding them in his secret captivity, along with the rest of the members of the Dragons, in safety.
However, it turned out that Dragons were soon discovered by the Reddosutā Shikaku and attacked. Machine and Sapphire escaped but only when Machine realized it was too late, he had left his sister behind and traveled to Kanto to start a new life. The Reddosutā Shikaku are currently back in action, searching within the shadows for their time to strike Machine and the rest of his family. And, because of the fact that Machine revealed their whereabouts to his friends, the Assassins will now have to kill them as well to keep their name and terrible past, a secret.