X (iX)

X (イクス), referred as "iX" to differ him from the original X (エックス), is a evil copy of X from the Carddass Rockman X Mega Mission. "iX" has the same abilities as X and is very aggressive.

Rockman X Mega Mission
The Limited Replibrain created by Dr. Doppler was absorbing data from the bodies of the Reploids defeated by X and Zero, and "iX" was created from the Limited after it absorbed Schmitt's body. "iX" fights against X, and during the battle, the Limited on X's arm evolved to the Clear Armor, increasing his power and making X able to stand against "iX". In the end of the battle, they shot each other at close range, and the shots destroyed "iX" and X's Clear Armor.

Rockman Remix
"iX" appears in the story Mega Mission from the manga Rockman Remix, which is based on the cards. When X's right arm was infected by the Limited on Wire Hetimarl L, X's gains a evil alter ego with "iX"'s appearance. The alter ego says to X that if they merge, he will become more powerful, and X becomes brutal when he takes control of his body. X tries to resist the merge, and changes between his original and evil personalities. During the fight against Schmitt, Zero says to X that the soul is more important than the strength, which is useless without feelings, giving X a better control over his body.

When the Limited absorbed Schmitt, "iX" was created and he attacked Zero from behind. With X angered, the alter ego manages to increase his control over his body, evolving X's High Clear Buster to the Clear Armor and fighting against "iX". During the battle, Zero stands between the two pretending he is protecting "iX". X, understanding Zero, attacks him and the shot only passes close, hitting "iX" while he was offguard. X also managed to get rid of the Limited alter ego by himself, and as result the Clear Armor is destroyed. "iX" is than absorbed by the Limited, evolving it to the Repligigant Mother Limited.

Return X
Return X (リターンイクス), RX for short, is "iX" from the first Rockman X Mega Mission revived. He appeared suddenly during the fight against the four Hyper Limit Reploids, and defeated them so nothing would disturb his fight against X. RX has great hatred torward X and wants to finish him with his own hands. During the fight, RX is shot in the back by Enemice HL, who also wants to destroy X by himself. Not wanting to share the battle with Enemice HL, RX decides to assist X and Zero against him, taking a liquid-like form and splitting into two to merge with X and Zero, becoming the EX Armor ("iX" Armor) to defeat Enemice HL. During the battle, Enemice HL uses the Sigma Chip to increase his power, but it takes control of his mind and he becomes Sigma Limited, taking Zero down. The part of RX that was on Zero moved to X, becoming the All X Armor (All "iX" Armor), but Sigma Limited was too powerful for them. To defeat Sigma Limited, X and RX combined their busters into a powerful Double X Buster attack, using a large amount of energy from them. The All X Armor begins to disappear gradually and RX used all of his energy, presumably dying in the attack, but X believes this may not be the last time he will see him. In the prologue, it is shown Return X had survived the battle, and he absorbed the Sigma Chip to increase his power. He plans to challenge X as soon as he recover.

Mega Armor series
Return X has a model figure based off of him in Bandai's Mega Armor series of models, coming in transparent and plated variants. The EX Armors of X and Zero and the All X Armor are also present in the collection, both models having a transparent and plated variants.