Iris

Iris is a Reploid that works as a Navigator for Maverick Hunters. She is also Zero's love interest and the younger twin sister of Colonel.

Appearance
Iris appears as a young-looking female brunette Reploid with green eyes. Originally, she had very long hair, comparable to Zero's length, but she decided to cut it after the Repliforce incident. Her armor consists of a blue and red scheme with yellow accents and is modeled into the form of a dress (coat post-Repliforce), her limbs being white, her boots white, and her hands appearing to have segmented knuckles. In Rise of Repliforce, her boots gain a black outline and have a defined lavender color with the addition of a red beret on her head. In Doppler Effect, Iris appears to be slightly younger.

After taking Gate's weird orb into her body in Rise of Repliforce, she appears as a Ride Armor-like being with a purple color scheme and a pair of wings. It is unconfirmed as to whether she entered a Ride Armor vehicle or became a similar being herself. However, she reverts to her original form after her defeat, suggesting that she was inside an armor.

Doppler Effect
Reploid scientist Gate attempted to develop an ultimate fighting Reploid with both a high fighting spirit and peace-loving heart, similar to X, but the differences were ultimately considered irreconcilable and the project was considered a failure. Gate then decided to split them up into two Reploids, resulting in the creation of Iris and her brother Colonel. Her half was of the peaceful arbitrator, and Colonel's was of the strong-willed fighter. Iris was originally intended to be a support for Colonel.

The project got the attention of the Maverick Hunters, and Zero went there to investigate. When Zero got there, it appeared that Gate created them with entirely pure intentions, but what Zero didn't know was that Gate was already infected by the virus (possibly thanks to Dr. Doppler). Despite this fact, Iris and Colonel decided to join the Maverick Hunters and help Zero make investigations on the X-Hunters, as Zero was feeling that X was acting suspicious. Iris did figure out that X salvaged all personality drives from up to date.

However, after the Doppler incident was solved, Iris decided to quit because she couldn't stand the fact that Zero was acting as if the Maverick Hunters were corrupted. Since Dr. Cain and, as Zero was believing, X were doing mistakes with originally good intentions, Zero apologized to Iris for being too focused on the wrong things.

Rise of Repliforce
For reasons unknown, the massive dragon-like Maverick Eregion kidnapped Iris. He then brought her to a large metropolitan city located underneath the aerial city of Sky Lagoon. And while under the influence of Magma Dragoon, he wreaked havoc on Sky Lagoon, drawing the attention of the Maverick Hunters. During this time, Dragoon would damage the core of Sky Lagoon beyond repair, while making it seem as if Eregion did it on his own. This caused the Sky Lagoon to fall on the populated city below, causing millions of deaths. Although Iris was injured, she survived thanks to the timely intervention of Zero at the ruins of the city. Repliforce field commander Colonel then arrived on the scene, thanking Zero for rescuing her. However, the Hunters suspected that Repliforce might have been involved in the disaster because of their proximity to the area at the time of the Maverick attack, and demanded that they disarm and come in for questioning. Colonel stubbornly refused to do so, and as a result the Repliforce were labeled as Mavericks, which lead to Repliforce launching a violent campaign for independence known as the Great Repliforce War.

After the Repliforce was labeled Maverick after the Sky Lagoon incident, both X and Zero were assigned different missions to gather information about Repliforce's coup, cut off their support lines and arrest Repliforce commanders. Iris assisted Zero on his missions as being his operator. However, her brother, Colonel, was Repliforce's second-in-command and therefore an imminent target for the Maverick Hunters. When Colonel and Zero battled in the Memorial Hall, it was Iris who stopped the two Reploids from terminating each other by begging her own brother to stop, since Zero had previously saved her life after the Sky Lagoon had crashed. Colonel, who had always regarded Zero as a friendly rival, backed off. Zero, however, knew that next time they'll meet, he'd have to kill Colonel, so Iris made X promise her to bring Colonel back alive.

When Repliforce's coup began, X rushed to the Space Port to stop the ascension of the military troops to the newly constructed space station of Repliforce, Final Weapon. There, he fought Colonel and won, but he brought Colonel back to Maverick Hunter HQ in pieces. Worse, when Colonel recovered, he called Iris a "traitor" and that, if she cared about him, she should prevent the Hunters from fighting General. Out of shame, Iris went to Gate, who gave her a purple orb, implied to be a power-up for combat. Later, at the Final Weapon, Zero had the unpleasant surprise to find Iris, who got there with Gate's help. Iris, blinded by the shame caused by Colonel's harsh words and anger for X breaking his promise, fused the orb with her own programming, and Zero was reluctantly forced to battle. Even though Zero didn't mean to cause harm to her, Iris was out of control due to her programming and Gate's power-up being in conflict, which was also damaging her. While Zero destroyed the exostructure resembling a Ride Armor around her, the damage to Iris' was irrepairable due to her power core being destroyed. Zero hurried to Iris's body, and while Iris layed dying in Zero's arms, she whispers to him that she did all this because, even though she knows it is nothing more but a fantasy, she wanted to live in a Reploid-only world together with Zero. After Iris says her "final" goodbye to her friend, Zero tries to get her to wake up, but fails and has a breakdown, questioning what he is fighting for and even shrieking for X to help him.

Luckily, as if he heard Zero's call for help, X came to help. When X realizes that, unless Iris gets a new power core quickly, she would die with no way to come back, Zero, out of guilt and shame, wishes he could give Iris his own power core. To Zero's surprise, X granted Zero's wish, making Zero and Iris share Zero's power core. At X's instructions, Zero and Iris left the Final Weapon. Later, Dr. Cain gave Iris a new power core, and Iris decided to give herself a makeover. Afterwards, Zero and Iris forgave each other for fighting each other, and promise to make the dream of living together in a world where humans and Reploids lived in peace, the world Dr. Light wanted to create.

Personality
Iris is a kind-hearted Reploid who desired peace for all. As the programming of Iris and Colonel was over 50% identical, they were very close and tended to protect each other no matter what. As a Navigator, she shows great concern for the safety of the Maverick Hunters, especially Zero. She was greatly distraught by the war between Repliforce and the Maverick Hunters, and often pled for the fighting to stop. Regardless, she sided with the Maverick Hunters for most of the conflict, supporting Zero. However, she seems to be a very fragile soul, as X breaking his promise allowed Colonel's words to make Iris snap.

Trivia

 * Since she and Colonel were created by Gate, Iris is one of the characters adapted in a unique way to connect her to a Maverick fans would never expect for that connection to exist, others being Signas (he's Sigma's reasonable side), Alia (she trained under Flame Stag) and Slash Beast (he's a clone of Neon Tiger)
 * Regardless of whether or not the Nightmare Investigators from Mega Man X6 appear in Chronicle 5, Iris is the only one of Gate's creation to not be a Maverick. According to a fan, Colonel actually is a Maverick, as he toyed with Iris' feelings.
 * Should the Nightmare Investigators appear in Chronicle 5, one would say that Zero, with some help from X, saved Iris from the fate suffered by the Investigators. In the games, the Nightmare Investigators fell victims to a conspiracy led by Gate's colleagues, who were jealous on the fact Gate was making so powerful Reploids. By taking her under his wing, Zero practically made it impossible for Gate's colleagues to dispose of Iris, as he wouldn't let anyone hurt her, especially not after he hurt her himself.
 * Iris' connection to Gate makes sense, as Iris is half of what was supposed to be the ultimate fighting Reploid, and Gate's goal in the games is to create the ultimate Reploid.
 * At first, it seems that Iris adopted some of Repliforce's beliefs, telling Zero she wished they could live together in a society of only Reploids. However, since, in the games, Gate also wanted to create a world where only high-end Reploids exist and, in X Chronicles, Gate was already infected by the time of the Repliforce incident, it might be possible that the power-up Gate gave Iris was meant to make Iris see things Gate's way.
 * This can be taken a step further: since the virus wants nothing more than to corrupt X and Zero, it might be possible that Gate set up the destruction of Sky Lagoon on purpose to make X and Zero kill Iris, in order to break Zero and make it easier for the virus to corrupt him.
 * Iris' death in the games got a lot of negative feedback from the fanbase, partly due to the game's bad voice acting, but mostly because everyone was feeling sorry for Zero and Iris. As such, Iris being alive by the end of Rise of Repliforce got a lot of positive feedback from the fans of the series.
 * However, it might be possible that Iris was alive only thanks to the nature of the series: all viral Mavericks and misjudged Mavericks were meant to be saved (save for General, who sacrificed himself to destroy Final Weapon), and Iris not only is connected with a group of misjudged Mavericks (Repliforce), but she was also created by a viral Maverick (Gate), and furthermore, she's not a Maverick at all.
 * In the Mega Man fanbase, Iris does have some competitors for Zero's heart (Layer from Mega Man X8 and Ciel from the Mega Man Zero series). However, the X Chronicles series ends with Chronicle 5 (which is most likely the X5 and X6 adaptation), so these competitors won't appear at all.
 * The fanbase constantly gives Iris the last name of "Thorne". However, Cyrex doesn't do that.