Metallix (Lilo and Stitch)

Metallix is a major character in the semi-canon "Metallix, Lilo and Stitch" series. He and his master, Dr. Koopa, are visitors from another timeline, who came here because of a threat in the space-time continuum was threatening their timeline. He is a doomsday weapon created by Dr. Koopa, in order to exterminate Dr. Koopa's nemesis, Mario. However, Dr. Koopa stated that Metallix's primary function is giving a happy ending to anyone who deserves one, and any kills he makes are required sacrifices, in the form of people who don't deserve a happy ending. By this logic, you can say that Dr. Koopa believes Mario doesn't deserve a happy ending.

In Kingdom Hearts: Birth By Sleep
Presumably after the events of "Zero and Iris' happy ending", Dr. Koopa noticed a massive anomaly in the time-space continuum, coming from Hawaii, 20XX. (According to the Lilo & Stitch franchise, it's between 2002 and 2006.) He and Metallix used a Time Stone to travel to 20XX. However, they arrived on Planet Turo rather than Hawaii, during the trial of Dr. Jumba Jookiba.

Shortly after the trial, Metallix and Dr. Koopa meet Terra, who was imprisoned for reasons unknown. The two wake up Terra, who noticed the Unversed. Metallix arms his Spin Dasher, but Terra informs him that only a Keyblade Wielder can defeat the Unversed. Dr. Koopa reveals the Keyblade of Chaos, an upgraded version of his Sword of Chaos he created in his insanity, by extracting seven pieces of pure light (from Iris, Sally, Alia, Bunnie, a random fox and, for reasons unknown, a Dark Legionary) and 12 pieces of pure darkness (from Robotnik, Naugus, Mammoth Mogul, Colonel, Sigma, General, Copy X, Zero, Mario, Serges, Violen and Agile). Terra then identified the sword as the legendary χ-blade, and wonders if Dr. Koopa is the 13th piece of pure darkness. Dr. Koopa denies it, claiming that the Sword of Chaos itself is the 13th piece of pure darkness.

The three defeat the Unversed, with even Metallix's Spin Dasher being effective (as Metallix copied some powers from the Keyblade of Chaos. Then they formally meet Jumba, who persuades the three to release him so that the two may rescue a "constructive" creature of his creation called "Experiment 626". Terra agrees, and the four set off to find 626 together. When they finally find the small extraterrestrial encased in a pod within the Confinement Room, Jumba sets him free and reveals that he is meant to be an evil and malevolent creature whose only instinct is to destroy everything he touches. 626 then rushes at Terra and steals his Wayfinder, the Keyblade wielder ordering him to return it because his "friend" gave it to him. Jumba later laughs off the idea that 626 could understand the concept of friendship, but he is greatly surprised when his creation drops the Wayfinder and scuttles off. Jumba finds Terra's theory that 626 isn't evil at all and merely craves friends impossible, and he gives him another demonstration of his "evil geniusness" by activating Experiment 221 for the Keyblade wielder to battle. Terra is victorious, and he and Jumba notice 626's return to the Confinement Room after 221 returns to pod form. Jumba watches Terra try to explain friendship to 626, but he angrily interferes with Terra's discussion, as things such as friendship would corrupt his creation's original purpose. He tells 626 that he needs to be fixed, but alarms begin to sound and an announcement is made that 626 and two prisoners have escaped. Terra flees Turo, leaving Jumba, 626, Metallix and Dr. Koopa behind.

When Aqua arrives on Turo, she is attacked by several Unversed. Finding a peculiar object in the shape of one of her good-luck charms, she studies it only to have it snatched back by Experiment 626. Angry with Aqua until he notices her Keyblade, he then runs with the approaching sound of Gantu's voice. Discussing 626 with Gantu and later meeting the Grand Councilwoman, Aqua is sent on a mission to eliminate the Unversed present in the world, as well as capture both the escaped Experiment 626 and Dr. Jumba. In the process, she finds 626 in the prison chamber, several Unversed prepared to ambush him. Aqua comes to his rescue, asking what the Experiment was doing in the chamber. He utters only a single name, "Terra", fleeing the chamber before Aqua can interrogate him further. Metallix and Dr. Koopa explain Aqua that Experiment 626 saw the good luck charm from "a man named Terra", who believed 626 wanted to make friends, and then 626 made his own. Despite her distrust seeing the Keyblade of Chaos, Aqua explains that this "man named Terra" is her best friend, and the "good luck charms" are called Wayfinders, which are meant to lead two close people to each other. This made the dynamic duo realize that 626, not wanting to forget Terra, created his own Wayfinder. Aqua later learns from the Grand Councilwoman that Jumba and 626 are now on the ship's docking bay, the Keyblade master going to them only to be attacked by Gantu. 626 and Aqua team up to defeat the alien Captain. Aqua later persuades the Grand Councilwoman to reconsider Experiment 626's sentence, as he has appeared to have learned the true value of love and friendship through the Wayfinder he made as a tribute to the one Terra has.

Unbeknownst to the Grand Councilwoman, Metallix and Dr. Koopa snuck aboard Gantu's ship.

When Ventus arrives, he is attacked by a massive Unversed, pursuing it to the Gantu's ship. Meanwhile, Experiment 626 has been recaptured, Gantu taunting only to be interrupted by an intruder. Told to stay put by Gantu, 626 uses his superior brain to escape his binds, the guns trained to fire only at him used to create a doorway and set the Experiment free. Gantu thinks Ventus is the intruder and does not believe his stories that it was a monster that was causing the trouble the ship was encountering, Ventus continues to pursue the Unversed that attacked him only to run into Experiment 626. He learns from the Experiment that he knows Terra and Aqua, 626 showing him his hand-made Wayfinder. 626 then attempts to follow Ventus in the trail of the Unversed, but is told to stay behind.

Waiting for Ventus, 626 stands in the chamber with his precious Wayfinder, only to have it destroyed by Gantu, who says that, while the Grand Councilwoman has reconsidered 626's sentence, Gantu not fooled by 626's apparent change in personality. When Ventus finally catches up to the massive Unversed, which was attacked by Metallix and Dr. Koopa, 626 appears before him, aiding him in the battle. Experiment 626's rage becomes uncontrollable during the battle, however, causing the small extraterrestrial to attack Ventus, who soon learns that 626's charm had been broken. Gantu soon appears and explains 626's destructive nature, the Experiment and Ventus flee as Gantu orders their capture. 626 goes on to steal a red police cruiser, Ventus following him on his Keyblade Glider. Experiment 626 activates the cruiser's faulty hyperdrive in order to escape his pursuers, and leaves Ventus behind in a blast of energy as the ship vanishes at light speed. Metallix and Dr. Koopa, however, couldn't keep up with him, and were captured by Gantu.

In Lilo & Stitch (2002)
As the Grand Councilwoman tries to figure out how to catch 626, Metallix proposes for Dr. Koopa to find Aqua and have her tame 626, although he also had the intent to bring Terra and Ventus to assist Aqua, since the three are friends. The Grand Councilwoman accepts, but is still unsure what would happen should the doctor fail. As such, she sent Jumba and Agent Pleakley to capture 626, in case Metallix and Dr. Koopa would fail.

Metallix and Dr. Koopa went back to their dimension to borrow an airship and an unfinished other Metallix, intended to be like a brother for Metallix. The unfinished Metallix was then upgraded to locate other experiments, as Dr. Koopa knew 626 wasn't the only one Jumba made and was fearing Jumba might unleash Experiment 221 on them to try and stop them. Dr. Koopa went to find Terra, Aqua and Ventus, while Metallix went to Hawaii 20XX with the airship, in order to find 626. The airship is somehow heavily damaged by 626's hijacked police cruiser and crashes in Kaua'i, alongside the cruiser.

Metallix thankfully survives, being built to be nigh-invincible thanks to his Evolution Module, allowing him to grow and adapt to any situation. He then locates 626 at an animal shelter and attempts to adopt him as a dog ("doggo", as he says it himself), only for a girl named Lilo Pelekai to be one step ahead of him: having arrived before Metallix and seeing 626, as well as being told that 626 was ran over by three trucks (as Metallix believes, shortly after his arrival), manages to adopt 626 and name him Stitch (apparently an illegal name to name a dog in Iceland, but since the setting is Hawaii...). Metallix then decides to hang out and try to befriend Lilo in order to get closer to Stitch, who seemingly resents having to be treated as a dog, despite being adopted by Lilo as one, and longs to see Terra, Aqua and Ventus. Metallix is also glad that Stitch managed to fix his Wayfinder (according to Metallix, this is coincidental, considering his name). When Stitch steals Mertle Edmonds' tricycle and Jumba claims that Stitch will look for large cities to "back up sewers, reverse street signs and steal everyone's left shoe", Metallix stated that, on Kaua'i, Stitch has a higher chance of finding Terra and Aqua than a big city. (This confused Pleakley, who didn't know who Terra or even Aqua were.)

That evening, as Lilo and Stitch eat dinner at the restaurant where Lilo's older sister Nani works, Jumba and Pleakley try but fail to capture Stitch. The resulting chaos is blamed on Stitch, causing Nani to be fired. The next day, Cobra Bubbles warns Nani that if she doesn't get another job, Cobra will have to place Lilo with a foster family. As Nani attempts to find another job, Lilo tries educating Stitch about Elvis Presley, whom she calls a "model citizen". However, Stitch's antics, including evading Jumba and Pleakley, ruin Nani's chances of finding work.

Nani's friend, David, invites Nani and Lilo to take a break and enjoy a day of surfing. While Nani, Lilo and Stitch ride on a huge wave, Jumba makes one final effort to capture Stitch from underwater, causing Nani to wipe out, and Stitch unintentionally pulls Lilo down with him. Although everyone gets safely to shore, Cobra witnesses this unfortunate event, telling Nani that although she means well, Lilo will have to be taken away. After seeing how much trouble he has caused, Stitch runs off.

Finally getting some alone time with Stitch, Metallix reveals that, deep down, the two are the same. He reveals to Stitch that, just like Stitch, he is meant to be a doomsday weapon, explaining how he once was a simple, organic Mobian named Sonic, but gifted with speeds no other Mobian has ever seen, but he ended up in a war with the evil Dr. Robotnik, war which he lost. Robotnik turned Sonic into a robot and sent him to the past to "rinse and repeat". Thankfully, Dr. Koopa upgraded the roboticized Sonic into "Metallix", and gave him the sole purpose of giving happy endings to people who deserve it, and kill anyone who doesn't. Metallix, however, knew that, since he doomed his friends as Sonic, he'd doom his friends, as well as Sonic himself, as Metallix, which can only mean he's nothing but a doomsday weapon.

Dr. Koopa then comes, having failed to find Terra, Aqua and Ventus, claiming that "it was too late" (Terra was possessed by Xehanort, Ven's soul was nearly completely destroyed, with only a fragment left, which was part of the soul of another kid, and Aqua was trapped in the Realm of Darkness.) Jumba, having been fired by the Grand Councilwoman, confronts the three, with the confrontation being dragged in Lilo's home, and when Jumba clogs up Metallix's Spin Dasher with a carrot and, alongside Stitch, prevents him from taking the carrot out, Metallix overloads and blows up, alongside the house, apparently dying.

In Lilo & Stitch 2: Stitch Has a Glitch (2003)
Thankfully, Metallix barely survived, albeit being reduced to a head and torso. Dr. Koopa, who, for some reason, was accepted as a member of the Pelekai 'ohana, as the 'ohana's "psychological balancer" (a fancy term Dr. Koopa created for "psychiatrist"), found his parts in the rubble and rebuilt him. By the next year, he was completely rebuilt. He often tried to calm down Lilo and Stitch when Stitch's glitches were getting in Lilo's way to win a hula competition.

When Stitch tried to flee, Metallix went Fleetway for a brief moment, trying to recharge him using Chaos Energy. When Stitch died, despite Terra, Aqua and Ventus being seemingly gone, Metallix still felt their energies, and brought them in a spiritual form to Stitch's "deathbed" using Stitch's Wayfinder.

In Stitch! (2003)
Sometime after Stitch was revived, Metallix learns some dark stuff about Stitch: first of all, Jumba brought all his previous 625 experiments with him. Secondly, Jumba had a past with the evil Dr. Jacques von Hamsterviel. Basically, Hamsterviel funded Jumba's experiments. However, the more experiments Jumba created, the bigger the disdain between Jumba and Hamsterviel in regards of the copyrights for the experiments. To prevent Hamsterviel from stealing his experiments, Jumba created an experiment meant to act as a failsafe in case Hamsterviel would steal the experiments, as well as an anti-Hamsterviel program. This "failsafe-experiment's" number is X-624, but Jumba forgot to install the anti-Hamsterviel program into her. As such, Jumba installed it into the next two experiments, X-625 and Stitch himself, with the intent of them uploading it into X-624. However, the anti-Hamsterviel program had some unexpected side-effects: X-625 ended up being lazy thanks to a glitch Jumba fixed while working on Stitch, and, in Stitch's case, the program made Stitch realize that, should the upload fail, he'll become an outcast among experiments, which is why Terra saw that Stitch wanted to make friends.

Metallix helped with capturing Experiment 221, later named Sparky.

In Lilo & Stitch: The Series (2003-2006)
Metallix appears in every episode, often being a morality bringer to Lilo, Stitch, Sparky, later Angel, and even later Belle. He also believes that Hamsterviel is more like a "filthy sewer rat" than like a hamster, as Hämsterviel claims.

The "Angel" story arc has the biggest impact on Metallix. After learning Angel was activated, he believed Angel had an icy heart that needed defrosting, and only true love would do it. When Stitch falls for Angel, Metallix, as well as Dr. Koopa, attempts to hook them up, subtly showing Stitch what he thought it was the right path. When Metallix notices that Angel was actually Hämsterviel's double agent, he shows his disappointment in Angel, stating that "last time someone broke Stitch's heart, he died and had to be brought back from the dead. If you know what's good for you, you'd better turn against that filthy sewer rat." When Sparky becomes jealous of Stitch, Metallix convinces him to act himself as a double agent - acting as if Angel turned him evil, but his motive being in fact being blinded by jealousy. Metallix's plan nearly works, but Gantu captures Angel and sends her to Hämsterviel as punishment for treason. This, however, causes Metallix to go Fleetway. When Ace was activated, Fleetway Metallix kills Mortlegax and attempts to blow up the entire city just to find where Hämsterviel was holding Angel. Luckily for the town's inhabitants, Ace somehow manages to push Metallix way beyond his limits, causing him to blow himself up. Like before, Metallix was reduced to a head and torso, being barely alive. After Stitch, Sparky and Ace free the experiments Gantu was holding on his ship, including Angel, who started dating Stitch, Metallix finally calmed down.

There also are moments when Metallix ponders if experiments can be altered by a Genesis Wave. For example, after rescuing Belle, Jumba stated that she "is more timid and has a larger body compared to the head than I remember", which Metallix and Dr. Koopa believe that it's because of the Super Genesis Wave, which is seemingly the reason they were there in the first place.

In Leroy & Stitch (2006)
Metallix and Dr. Koopa noticed all the experiments going missing, and found out that Leroy kidnapped them and attempted to destroy them all. Metallix's Spin Dasher and Variable Weapon System could kill some of Leroy's clones, but the Leroys soon got the upper hand. However, they were destroyed when Lilo, Stitch and Reuben started singing "Aloha 'Oe", which Jumba secretly installed in the original Leroy as a failsafe.

Metallix and Dr. Koopa soon realized the timeline is fixed, and bid goodbye to them, but not forever. Dr. Koopa and Jumba built a interdimensional transport device locked on Disney Town, stating that they'll meet each other there one day.

Before and after this mess, Metallix's past and future are virtually identical to his hardcore counterpart.

Personality
Metallix appears as an extremely wise robot, often acting as a mentor to Lilo, Stitch, Sparky, Angel and Belle. He enjoys nothing more than to see the happiness of others, and would do any good deed partly for the sake of being good, and partly because he wants to make others happy.

However, Metallix is intolerant of any mistakes. An example is Yin and Yang: Lilo thought Yin, a female experiment, was male, which prompts Metallix into dope slapping her. Furthermore, he hates it when true, pure love is not fulfilled, as Angel being captured after finally realizing she had true feelings for Stitch caused Metallix to go Fleetway.

Appearance
Metallix is a blue, hedgehog-themed Reploid. He sports blue armor with silver outlines and a red crystal on his chest. This appearance is practically identical with his hardcore counterpart.

Special powers
Metallix is an extremely, ridiculously powerful Reploid. His Variable Weapon System and Evolution Module makes it really easy for him to adapt to any situation. (Mostly, a rogue experiment. Not excluding others.) Furthermore, when his rage, hatred and/or desperation reaches peak levels, he transforms into the virtually invincible Fleetway Metallix, who is stronger than all experiments altogether, and can only be defeated by lasting against him long enough for him to overload.

Weaknesses
Despite Dr. Koopa claims Metallix has no weakness, some of Metallix's actions show otherwise. First of all, if you clog up his Spin Dasher or prolong a battle against Fleetway Metallix too much, Metallix overloads and blows up. He also is not immune to Spooky's powers, as Spooky transformed into a wounded Tails to discourage Metallix.

Trivia

 * Metallix is the only artificial lifeform in the series to not be an experiment. Instead, he's a robot.
 * Metallix's transformed state being called "Fleetway" Metallix is ironic, since Metallix's real-life copyrights belong to Fleetway Editions. This state might as well be called "Super Metallix".