X9 was a skilled and intelligent assassin built by scientists under the employ of Aku. He was forced out of retirement by Aku to destroy Samurai Jack. He made his first appearance in Episode L: Tale of X9.
Due to the experimental personality chip placed in him by his creator, he was able to develop a personality and emotions. He admits to hating rain, particularly because it makes him sentimental. When he was ordered to kill people, he admitted he hated it and that he grew to understand what was right and wrong, and that what he did was wrong. He was the only one of his model to survive, because he was smart and possessed a will to live. He was also angered as his fellow x robots were all murdered without a will to live or die. He developed a strong attachment towards a dog whom he would name Lulu. His love for Lulu was so great that when Aku kidnapped her to force him to fight Jack, he decided to face Jack knowing he wouldn't win after seeing his skill but desperate to try and save the one thing he loved. During his retirement, he seemed carefree, laid-back and relaxed, not caring about the years that flowed by and enjoying jazz music. He despised his former line of work and didn't enjoy the idea of having to hunt down Jack. He was also smart enough to track Jack down and asses his skill with a sword from the carnage of robot parts he left behind. He seemed humble about his skills and knew his limits, as he quickly assessed Jack would most likely be able to beat him.
X9 was one of the early models of Aku's combat drones, the X-series, designed and constructed by the very same scientists who would later create the Beetle drones. However, unlike his fellow bots, X9 was bestowed an artificial emotion chip by one of the eccentric scientists who "was funny like that." This additional software gave X9 an edge among the other drones, able to think on his own and realize that he was not willing to die but rather live. As a result, he managed to survive all of his missions while the rest of his unit were all destroyed, and quickly became one of Aku's most powerful soldiers. He had also developed strong emotions often regarded as human-only, such as loathing, guilt, and unconditional love. Prime examples of this would be his feelings towards a stray dog that he named Lulu, his contemplative admiration of jazz music, anger towards the deaths of fellow X-series models that did not care whether they lived or died, and a visible regret for carrying out executions. X9 was also noted to have hated rain as it made him feel sentimental.
During the early years of Aku's reign, Aku's impatience at his own progress inspired him to create an army of robots. After several crude and pathetic prototypes the X-Models were created. One of Aku's scientists, for no reason other than the scientist's own eccentric nature, installed an emotion chip into X9. The X-Models were then sent to hunt down Anti-Aku rebellion members. X9 recalled his emotions causing him to recognize the amoral nature of his duty.
Having emotions, X9, unlike his brethren, cared whether he lived or died, and survived future battles due to that fear. However, he also grew angry at the sight of a fellow bots' destruction. At the creation of the Beetle Drones, X9, the last of his kind, was rendered obsolete. However, shortly before this had occurred, he found a dog after a mission that he named Lulu. After retiring, X9 became content with living his life by playing the trumpet for Lulu. Eventually though, after learning of X9's emotions from the same scientist who gave them to X9, Aku kidnapped Lulu and gave X9 a simple ultimatum: kill Samurai Jack or Lulu dies. X9, having no options, came out of retirement. He easily found Jack from the trail of destroyed Beetle Drones, and admits from the apparent proof, that his (X9's) chances of winning would have been slim to none.
After finding Jack in an abandoned Beetle Drone factory, X9 cautiously entered, and a deadly game of cat and mouse ensued. Finally, Jack used an old inactive X-model as a decoy which X9 gunned down accidentally. However, this moment of distraction was all Jack needed and stabbed the assassin, with the two never having actually seen the others face. As he shuts down (or rather, dies), X9 begged Jack to take care of Lulu. As Jack looks back sympathetically, the story closed on a photograph of Lulu... sweet thing.
Abilities and Skills
As an assassin bot, X9 was already provided with certain skills that fit his programming, but due to the personality chip that was implanted in him he learned at least one other, more human than machine skill. Despite being considered an outdated model, he managed to last much longer against Jack than many other droids due to the personality chip imbuing him with his own will:
- Master Gunslinger: Due to his pre-existing program, X9 possesses excellent skill with his twin pistols in terms of accuracy and efficiency.
- Expert Tracker: He has also show himself capable of tracking Samurai Jack easily, although by his own admission it was quite simple due to Jack's battles with Aku's drones or bounty hunters.
- Expert Musician: X9 has also shown himself to be a great trumpeter as shown when he frequently played in his home for Lulu.
- Many fans of the show felt sad for X9, losing Lulu, the only thing he loves and not keeping his promise to kill Jack.
- His main design theme suggests a sort of either government assassin, or a mobster (likely the latter, given his love for jazz music). Because the episode has a noir theme to it, it's more likely that X9 was based off of a noir detective.
- X9 is the first villain that Jack has some sympathy for upon destroying. The second time he is shown having sympathy for a slain opponent is in Episode XCIII.