Knives Millions(ミリオンズ・ナイブズ Mirionzu Naibuzu) is the main antagonist of Trigun, and the twin brother of Vash the Stampede.
As a child, Knives was a kind and caring young man, much like Vash, but more innocent. In the manga, Knives was more curious about Humans than Vash and wondered if they would accept them while studying Earth's history. Knives's hatred towards humans began when he and his brother discovered the abused remains of Tesla, an independent Plant that was "born" before himself and Vash. Both of the boys are shocked when they discover Tesla, and, seeing what humans did to her, he can no longer trust humans because of their cruelty and lack of self-control. Seeing Tesla's abuse also caused Knives to begin inflicting pain on himself whenever he was left alone
In the anime, Knives's resentment towards humans begins when a SEEDS crewmember, Steve, abuses him. After Knives finds out that Steve was also (verbally) abusing Vash, he begins to question why he is really "here". While Rem cuts Vash's hair, Knives leaves while they are talking and comes to a realization that "It is all wrong." After Vash finds him and discovers that he had cut his own hair, Knives explains that he had a change of heart. While in the Recreation Room of Project SEEDS, Vash, Knives, and Rem notice that a butterfly is caught in a spider's web. Seeing Vash's attempt to save the butterfly, Knives instead kills the spider, saying that it was "the easiest way to save it." After the incident with Roen and Mary, Knives agreed with Joey when he opened the airlock, sending a dead Mary and Roen (still in his crazed stupor) into space. Despite having thought that he did the appropriate thing himself, Joey then began to think if Rem was right, saying that Roen wouldn't have shot her. Knives then kills Joey, and alters the ship's course so it would crash into the planet. However, Rem is able to save the passengers and changes Project SEEDS's course so it wouldn't crash, ruining Knives's plan to kill everyone on the ship.
Throughout the anime series and the manga, Knives is portrayed as a psychopathic, cruel, and sadistic character, even to his colleagues, the Gung-Ho Guns. Even though Knives despises humans, he still has a caring relationship for Vash, and wants for him to join him on his quest to eliminate the humans for what they had done to the Plants.
After Knives and Vash escape the SEEDS ship, they crash land on the planet Gunsmoke, not far from the other ships. Knives talks with Vash about joining him in destroying the Human race. However, upset that Rem had just passed away, Vash refuses, but follows Knives since he does not want to be alone.
After fifteen years of wandering Gunsmoke, Knives and his brother come across a specific piece of a SEEDS ship. Leaving Vash alone, Knives goes alone into the ship in search for two .45 Long Colt revolvers. After a year of searching, Knives returns and gives a silver revolver to Vash, keeping a black one for himself. However, Vash was uncomfortable having a gun (keeping the pacifistic ideals that Rem had taught him), and shoots Knives unintentionally in his right thigh. Terrified that he had hurt another (especially his brother), Vash runs away, leaving an injured Knives behind.
Several years after that incident, Vash discovers that one of Rem's last surviving relatives is still alive, and living in the city of July. He does find the man related to Rem; however, he also finds that Knives murders the man, breaking all connections between him and Rem. Left utterly dumbstruck, Knives takes his left arm, and once again offers Vash to join him. He somehow controls Vash's remaining arm, and summons the Angel Arm. However, Vash aims the Angel Arm at Knives, and fires it, destroying all of July and nearly killing Knives as well.
Even though Knives was nearly killed in the July incident, he slowly regenerates, and later forms the Gung-Ho Guns to act for him in his stead while he recovers. Like the manga, the Gung-Ho Gun's purpose was to eliminate Vash, however there are no special coins that Vash had to collect. However, despite never actually killing the Gung-Ho Guns himself, they were either killed or committed suicide rather than to go back to Knives and admit their failure. Eventually, after all of the Gung-Ho Guns are dead, Knives himself waits for Vash to find him.
Vash manages to find Knives, and the two have a massive battle. Because of his better knowledge of the Angel Arm, Knives gains the upper hand in the beginning of the fight, Nearly killing Vash with his and his brother's guns in the Angel Arm form. However, with Wolfwood's Punisher cross, Vash disables Knives by shooting him in both of his shoulders and thighs. Then, falling unconscious, Knives is taken back to the village by his brother where Milly Thompson and Meryl Stryfe await Vash's return.
Knive's' fate is unknown in the anime, but in the ending of the series he is shown to have been bandaged from his final fight against Vash.
Many years after the Big Fall, the two meet in the city of July. Knives takes control of Vash and activates Vash's Angel Arm. Trying to control the power Vash points the arm at Knives as it fires. Knives is left in a very critical state. He slowly regenerates over a period of time after being placed inside a plant, and forms the Gung-Ho-Guns to act for him. After the plant gives birth to a regenerated Knives (killing the plant in the process) knives visits a town with a dying plant. He witnesses the plant's last death throes as the towns occupants send it through one last "run" to retrieve any resources left from the plant. The plant begins to turn black and dies. He is then informed that his power is finite and he will slowly die by using his abilities. This is evident by a black strand appearing in his hair showing the process has already begun. In order to continue with his plans of destroying the humans he begins absorbing other plants into himself, which causes his powers to grow exponentially.Knives launches "The Ark", a floating ship designed to leave humans without any resources by absorbing their plants. As he absorbs more and more plants, his Ark takes on the form of a sentient organism, capable of defending itself and, in some cases, even teleporting short distances. Vash and Knives eventually fight for a final time, and with the help of the humans Vash is successful in breaking Knives's control over all the other plants. Robbed of nearly all of his remaining power, Knives and Vash clash one last time, before escaping together from the vengeful ships from Earth. The two apparently make peace and take refuge at an isolated house occupied by a father and son, who provide the wounded pair with medical care. Knives seemingly uses the last of his power to raise a small fruit tree beside the house as a final gift to the father and son and to Vash, and seemingly vanishes afterward. He is never seen again (probably died due to loss of his energy and as Plants die, he withers).
Knives understands his origins and powers better than his brother Vash, and as a result he knows how to tap into his powers and create weapons such as the Angel Arms. The catalyst required to activate them is hidden above the barrels of he and Vash's revolvers. These power cores, when held in either of their hands, transforms the guns into weapons with immense destructive potential. It can cause their arms to morph into miniature versions of one of the SEEDS guns, the true power of the Angel Arm. Even at 13% of its maximum output, the results are nothing less than devastating.
Knives is also a powerful telepath, using his ability to manipulate other plants, evident in two flashbacks (Ep. 26: "Under the Sky So Blue"): when he almost causes a plant to combust in order to kill humans, and the instance in which he manipulates Vash's Angel Arm. He can also use this power on humans, evident in Episode 17: "Rem Saverem". In this episode, Knives kills the crew members one by one via manipulation and the apparent insanity that the crew members seem to suffer from.
In the manga, the Angel Arm is a natural ability of a plant, and does not require a special revolver to utilize. Knives' power manifests itself as an array of monomolecular wire/extremely sharp blades. Also, Knives further learns how to increase his power by merging with other plants, demonstrated on multiple occasions in the manga where he absorbs his "sisters" into his left arm, taking their power source into his. This power, however, includes a side effect; when using his power, parts of the plants he has absorbed can be seen. Arms, legs, and the occasional horrified face peek through the cloak he wears from his left shoulder to keep it concealed. Later he tries to use this ability to absorb his brother, Vash, yet he is almost overpowered due to Vash's more potent "flow." In this instance Legato steps in to pull Knives away from the brink before he is lost.
After fusing with thousands of plants, Knives launches "The Ark", a floating ship which travels around the Planet Gunsmoke, absorbing almost all the plants on the planet. This results in the near total collapse of human civilization on Planet Gunsmoke, as cities are left with no means of producing power, water or food. He claims that when he removes all the plants, the humans will kill each other over resources, thus proving to Vash that that is all humanity is good for. As he absorbs more and more plants, his Ark takes on the form of a sentient organism, capable of defending itself and, in some cases, even teleporting short distances.
- Adult Knives Millions anime voices: Tooru Furusawa (Japanese), Bo Williams (English)
- Young Knives Millions anime voices: Masamichi Ota (Japanese), Joshua Seth (English)
- Given their age at the time, their turning points match up with when most children would be learning basic shapes and colors, appropriate given how their fundamentals were based entirely on what they saw on that ship, much like how humans understanding of shapes is formed by what they see in the beginning and what thoughts come to mind with specific colors. Given what Knives saw and how he was left to brew on it, it is easy to see why he might have developed his violent logic.
- It is very slightly hinted at that Knives could be the younger of the two. Vash is his older twin brother, being born in a plant.