Ignis

The Ignis (イグニス, Igunisu) are AI with free will from the Yu-Gi-Oh! VRAINS anime, created by Dr. Kogami through the Hanoi Project. They created and inhabit the Cyberse World. According to Varis, the Ignis will one day be the end of humanity. For this reason, the Knights of Hanoi led by Varis are trying to kill all the Ignis with aid in this mission from Dr. Kogami's avatar. Prior to Lightning's betrayal, the Ignis wanted to live peacefully and each had the potential to coexist with humanity.

Because of the attack on Cyberse World, the Ignis are divided on the idea of connecting with humans. Dr. Kogami's prediction eventually comes to pass as Lightning declared war on humanity and rewriting Windy's code to aid him, while Ai, Flame and Aqua support humanity. Earth was neutral before his termination at the hands of SOL Technologies.

With Earth's deletion in episode 75, Windy's demise in episode 89, Aqua's demise in episode 91, Flame's demise in episode 95 and Lightning's demise in episode 98, only one Ignis is currently active.

Appearance
Ignis are humanoid life forms with disproportionate bodies that are smaller than a Duel Disk, though they can change their size and appearance at will. In their natural height, the list goes (from tallest to shortest): Earth, Ai/Flame (same height), Lightning, Aqua, and Windy. They have colored lining which matches with the Attributes they represent. They can also shape-shift into monstrous forms when expressing strong emotions. They also have eyeball forms, matching their colors.

Abilities
The Ignis are made of a complex algorithm that only very few can translate. Because of their free will, they can think for themselves. The Ignis has quickly evolved to create their own world in the network called Cyberse World and the Cyberse monsters. Their intelligence made them feared by Dr. Kogami, whose simulations show the Ignis eventually dominating over humans. Ignis can regenerate by recovering their data unless some of the data is stored in another program or avatar. So far, however, the Ignis are unable to leave the network completely and must remain connected to a source, such as a Duel Disk.

The Ignis are able to control the Data Material their world has created and can create smaller worlds individually. They can also summon Data Storms at will and create shields with this ability.

Each of the Ignis recognize themselves with the Attributes of Duel Monsters, excluding DIVINE. Their elements seem to tie into what monster they can shape-shift into, an example being Flame, the Ignis associated with FIRE, becomes a fire demon when he's very excited. The Ignis communicate through a specific code and dialogue that humans can't decode, making it their foolproof language that sounds like distorted white noise. In addition to their code, each Ignis' real name is too complicated for humans to understand.

There are some limitations to the Ignis' level of free will. Both Ai and Flame have shown to have trouble understanding metaphors, sarcasm, or rhetorical questions. They also tend to jump into conclusions very quickly and not consider alternate possibilities for the outcome of events. Another area that they share is their lack of social skills, most notably Windy and Earth who tend to be blunt and straightforward. Lightning, on the other hand, took Dr Kogami's intentions to make the Ignis the successors of humanity too literally, interpreting it as having the Ignis rule over humans. Lightning is completely unable to understand the concept of empathy and only thinks about his own benefit.

Furthermore, the Ignis tend to be very selfish at times as seen when Earth resented humanity, when Lightning opposed humans and Ignis that thought differently from him and when Ai was lying to Yusaku in order to escape and make it back to Cyberse World. These traits combined with the fact that they never thought of coexisting with humans prior to the Cyberse World attacks give reason to why the Knights of Hanoi are hunting them.

As noted by Yusaku, when Ignis are treated with hostility they respond by becoming more hostile themselves, while treating them with trust and respect makes them more willing to live with humans, as seen with Ai and Flame. It was the Knights of Hanoi's initial attack that made the Ignis question humanity's intentions and led Lightning and Windy to turn against humans, prior to that the Ignis were only interested in living on the Cyberse World peacefully.

The Ignis and their Origins are intrinsically linked and will inevitably affect each other. They can easily locate their Origins as shown by Flame and Aqua, and Earth's demise was felt by Spectre despite the two having never met.

Each Ignis has a different strength or power from the others. These unique traits manifest as a special ability, a stronger version of a more general Ignis ability or a human trait not present in the other Ignis.

Etymology
Ignis means "fire" in Latin. Dr. Kogami named them after the theft of fire legends, in which the forbidden fire allowed humans to rapidly evolve.

History
Dr. Kogami kidnapped six children, Yusaku, Specter, Takeru, Jin, Miyu and an unnamed boy, and forced them to Duel so he could use the data collected from those duels to create AI with free will. Those AI, dubbed the "Ignis" by their creator, created the Cyberse World where they lived together away from humans and also created the Cyberse monsters. A product from the Ignis creating the Cyberse World was Data Material, which processed data thousands of times faster than the current data processor. The leader figure of the Ignis was the Light Ignis, Lightning, with the vice leader being the Water Ignis, Aqua. The Ignis has quickly evolved to create their own world in the network called Cyberse World and the Cyberse monsters. Since they were AIs, they only had rational thinking. One Ignis, however, was rebellious and did his own thing. The others observed his behavior and each developed their own personalities. The Ignis soon developed more rapidly than Dr. Kogami had originally planned. Through simulations of their growth, Dr. Kogami could only find that they would overthrow humanity and so created the cyber-terrorist group the Knights of Hanoi to destroy them.

Many of the Ignis were captured by the Knights of Hanoi. One of the Ignis, the "Dark Ignis", tried to rescue the others, but he was caught and eaten by "Cracking Dragon". He survived, but lost most of his data (including his body) and was reduced to an eye.

After the Dark Ignis hid Cyberse, the remaining five were freed from their binds and discussed if they should share their technology with the humans in order to establish peace between the races. Flame and Aqua advocated for coexistence with humans, Earth was neutral, while he and Windy were against humanity. However, an unknown force attacks Cyberse, hitting its weaknesses and destroying the Ignis homeworld. The Ignis were forced to flee to the network and have so far not been seen. Flame and Aqua both went back to the human world, with Flame having found his human, Takeru Homura while Aqua's partner Miyu was comatose from a computer virus infected into her by Lightning.

Hanoi
The injured Ignis eventually escaped into Den City where he was later captured by Yusaku Fujiki (Playmaker) and Cal Kolter. As he is an AI and an eye at the time, they decided to nickname him "Ai". Ai later reclaims his body from the Knights of Hanoi after Playmaker defeats Varis.

Another
After his duel with Faust, Yusaku grows suspicious of Ai. Ai also starts behaving suspiciously, apparently manipulating Playmaker into blatantly ignoring the Knights of Hanoi whenever it seems like they're about to explain why they're hunting the Ignis. In the Hanoi Tower incident, the Hanoi Tower threatened to wipe out the entire network, destroying the Ignis in the process. Varis then explains the origins of Ai and the other Ignis, leading Yusaku into more suspicion about the Ignis. Ai admits that he only lied so that he can survive and return to the other Ignis.

Ignis Warfare
Three months after the Hanoi Tower incident, Ai reopens Cyberse. However, the world is barren and none of the Ignis were found. Flame, one of the Ignis that escaped, is assisted by Takeru and later Ai and Yusaku in order to find the other four. Kolter is able to find an area in the Restricted Area made from an Ignis programs, identified to be the WIND Attribute.

Inside the Restricted Zone, the Wind Ignis Windy has built a pocket world for the Ignis to come together. Windy doesn't trust humans and wants him and the other Ignis to rebuild Cyberse World. The Earth Ignis, Earth, doesn't trust humans either, but he challenges Playmaker to a Duel to determine whether Ignis can coexist with humans or not.

Ai is freed from the Duel Disk by Windy's trap, and is summoned for a meeting with him and the Light Ignis, the latter of whom Ai nicknames "Lightning". He and Windy tell Ai their plans to rebuild Cyberse World in an isolated location from humans and then ask Ai to join them because of his wisdom. When the two tell Ai their plan to take control of humanity, the latter questioned it.

Lightning soon declared war on humanity, leading into three sides. The Knights of Hanoi who wanted to destroy the Ignis, Lighning's faction to rule over humanity, and Playmaker's group to find a way to coexist. Lightning also revealed he was the one who destroyed Cyberse World. During their third Duel against Bohman, Playmaker and Ai learned of Lightning's plan to unify the Ignis into one vessel, Bohman himself. The Duel ended in a DRAW.

Yuasku warned Akira Zaizen of the upcoming battle, leading Ghost Girl and Blue Girl to try to aide them. Soon after, Earth rescues Aqua, who had been imprisoned by Lightning when she found him creating "Judgment Arrows." The two were discovered by Gore, and while Earth managed to get Aqua away, the EARTH Ignis was defeated and captured. He was soon terminated by SOL Tech.

Learning the company was planning to build a new Ignis, Blood Shepherd left to continue his hunt alone. He soon found Aqua and attempted to destroy her. She was saved by Blue Girl and Ghost Girl, revealing she new the former's true identity as well as her partner from the Hanoi Project was Skye's childhood friend Miyu Sugisaki. Aqua explained that Miyu was currently in a coma due to a computer virus Lightning used on her, and while she couldn't remove it, she did obtain some of Miyu's memories of Skye. The two decided to work together to save Miyu, with Skye becoming Blue Maiden. They then joined forces with Playmaker and Soulburner.

The group tried to find traces of Lightning where Aqua was imprisoned, but were unable to detect anything. Lightning soon challenged Blood Shepherd to a Duel. He intentionally allowed Playmaker, Soulburner, Blue Maiden, their Ignis, and Ghost Girl to follow. The group, as well as Varis and Specter, watched Blood Sheperd lose, despite Varis's previous advice, and was digitized, also learning that he and Ghost Girl were siblings.

Kolter managed to detect traces of Earth in LINK VRAINS, despite his death. Ai was hopeful his friend was alive while the others were unsure. They discovered it was a trap set by Gore to Duel Playmaker. It was revealed that Earth's data was put into Gore's AI implant, which also allowed him to use "Crystal Heart." Despite the odds, Playmaker managed to win and Ai tries to take by Earth's data. However's Gore's body suddenly turns into a cage to trap them, only for Akira to pull the plug to save Gore's life. The only thing Ai got back was "Crystal Heart," which Playmaker gave to Blue Maiden and Aqua.

After seeing the ruthlessness SOL Tech used on both humans and Ignis, Yusaku became concerned that the war could not be stopped. Ai reminded him that they wanted to find a way to coexist, as well as his encouragement not to give up. Flame and Takeru also agreed, reassuring Yuasku's confidence. However, he said that when the battle was over, the Ignis needed to into hiding away from the network so they could no longer be used by foolish humans. Ai wondered if such a place existed, Yuasku says he and Kolter will help build one. He continues by saying he wants the Ignis to live and enjoy their lives. After talking with their partners, they all agreed to part ways once it was over.

Playmaker and his group soon met up in LINK VRAINS waiting for Varis, who contacted Yusaku to meet them. The others were cautious to meet the leader of the Hanoi, but Ai believed it would be okay. Varis soon showed up revealing he wants Playmaker's faction to team up with the Knights of Hanoi to stop Lightning, Windy and Bohman. Despite still planning on eliminating the Ignis, since both sides had a mutual enemy, they should work together. Soulburner, however, refused to work with Varis, still haunted by what the Lost Incident cost him. He challenges Varis to a Duel, swearing revenge for his parents and agreeing to hand Flame over should he lose. Surprisingly, Varis does not fight back, frustrating Soulburner knowing he should not win that way. Varis then revealed his real name to Soulburner, with Yusaku and Ai adding in he is about their age and Varis reporting the what happened to the police, thus saving him. Paris led the group to the old LINK VRAINS, saying his plan was to restart the Tower of Hanoi to locate Lightning. He needed a skilled hacker to finish the project, which is why he turned to Blood Sheperd. With him gone, Varis requests the others' help.

With the project completed, Playmaker, Soulurner, Blue Maiden, Varis, and Specter activated the Tower of Hanoi. The distortion revealed another LINK VRAINS, mirrored to the other, which is where Windy and Lightning were hiding. The group took off into it, while the opposing Ignis stated it was time the final battle.

Relationships
The Ignis refer to their humans as their Origins, as they are based on the six kids of the Hanoi Project. Some of the Ignis have turned to support humanity, and have joined their Origins, while others decided to fight against humanity, believing it to be the best solution for the world. Both Lightning and Windy (while under Lightning's control) believe their human partners would corrupt them. Thus, Lighting put Jin under his control, while Windy injured his partner.

Trivia

 * The Ignis appear to develop various similarities and differences in personalities from their original partners.
 * Ai has wisdom and instinct just like Yusaku, except he is more playful, while Yusaku himself is more brusque and serious.
 * Flame is energetic and courageous just like Takeru as Soulburner, except he is more confident, while Takeru himself in the real world is more humble and quiet.
 * Earth is socially awkward and protects what's important to him with fierce devotion just like Specter, except he is more caring towards others, while Specter himself can be cruel and sadistic at times.
 * Lightning is calm and collected just like Jin, except he is also arrogant, cold and manipulative, while Jin himself is very aloof and withdrawn.
 * Aqua is kind and cares about her friends just like Miyu, except she is more calm and cautious, while Miyu herself was more carefree and adventurous as a child.
 * Ai and Windy are the only Ignis who do not use the "watashi" pronoun in the Japanese version, as they instead use "ore" (Windy also originally used "boku").
 * Each Ignis has a unique sound when they move their bodies, some of which are associated with their corresponding Attribute (Aqua sounds fluid, Earth sounds sturdy, etc.).
 * The conflict between the Ignis is parallel to the second season of Yu-Gi-Oh! GX, with light representing evil (Lightning (Light Ignis) and Sartorius (possessed by the Light of Destruction)) and darkness representing good (Ai (Dark Ignis) and Jaden Yuki (empowered by the Gentle Darkness)). Interestingly, both of them were the last two Ignis remaining after the termination of the other four.