Replicas

Replicas (レプリカ, Repurika), also referred to as "Puppets", "Phantoms" or "Clones" by some other characters, are a race of creatures in many worlds, and beyond. They are distinct artificial copies of another existing being. Either through by virtual reality projections created by Infinite with the power of the Phantom Ruby, or a special type of Nobody.

The first successful Replica in Vexen's first batch is Riku Replica in Kingdom Hearts: Chain of Memories. The first and only Replica of the second batch is later revealed to be Xion, (the fourteenth member of Organization XIII), Experiment No. I in the Organization's Replica Program.

In Kingdom Hearts II, Vexen will make Clone Soras during the optional battles against him. In Kingdom Hearts III, Vexen is ordered by Xehanort to create a third batch: twelve Replica Xehanorts superior to any past Replica. Additionally serving the Eggman Empire, replicas have all the strengths and powers that their original counterparts possess, though they have no free will. Each replicate can also be mass-produced.

In the manga adaptation of Kingdom Hearts: Chain of Memories, Vexen makes 44 Replicas of himself, which survive into Kingdom Hearts II.

"Infinite can create virtual reality projections. They have mass and form, but no heart or soul." "Virtual reality? So all those familiar faces that were a part of Eggman's army..." "Replicas. The problem is, they may not be real, but their powers are as formidable as the originals."
 * —Shadow and Sonic, talking about Replicas.

Anatomy
Replicas, as the name implies, are virtual reality projections of existing lifeforms. The replicas take on the form of their original counterparts, with little to no differences between comparing the original to the fake (the replica of Shadow is shown to have different eyes than the original Shadow, namely having slitted, cat-like pupils). It is also worth noting that the replicas will occasionally have red pixels randomly appearing on their body, a likely factor from the Phantom Ruby's abilities.

Characteristics and Culture
Replicas (also referred to as "puppets" or "clones" by some other characters) are synthetic copies of other people. While the exact method of creating a Replica is unknown as of yet, they have been shown to be able to be created out of different materials. Riku Replica was created using data collected by Vexen from his fight with the real Riku. He believed he was the real Riku due to Naminé's memory manipulation.

Xion, an imperfect Replica of Sora, was also made by Vexen and later altered by Xemnas. She was created from Sora's memories, but looked so different from Sora because the memories she was made from took the physical appearance of Sora's most important and strongest memory: Kairi. Replicas, like Nobodies, fade into Darkness after they are defeated. Xion, however, was absorbed by Roxas, therefore she continues to live on inside him, and inside Sora.

Most Replicas have a mysterious, stoic nature and very seldom give straight answers. Also, a trait shared by all Replicas shown in any version of the series is that they are very sensitive about the fact that they are copies. Riku Replica, upon learning he was a Replica, constantly referred to himself as "fake" and became obsessed with trying to become a different being than Riku. Xion even refers to herself as a "puppet" after she learns of her existence. In the manga, the Vexen Replicas are very quiet and sad compared to the original Vexen, telling the Riku Replica that "we are all failed replicas.". However, the manga is non-canon.

In Kingdom Hearts III, Master Xehanort's Thirteen Seekers of Darkness reinstate Vexen to continue the Replica Program. According to Vexen himself, his new Replicas can become real enough to exist as a being in their own right, for example, to serve as "permanent" receptacles for time-travelling Seekers of Darkness (Young Xehanort, Ansem, Xemnas, Vanitas, and maybe Dark Riku and Xion), unlike previous models that were more similar to Nobodies, and could only temporarily contain hearts from another era.

Powers and Abilities
Replicas are capable to using any ability that their original counterpart can utilize. The replica of Zavok, for example, is capable of fighting against Sonic in a brawl with both the personality and strength that the original Zavok has.

Abilities
Replicas seem to have a few unique abilities. Replicas appear to be able to fight as soon as they are created, not needing to learn fighting techniques or become stronger. This is most likely a trait passed down from the person they were created from. The most prominent ability Replicas have is the ability to absorb the life-force of other beings, increasing the Replica's overall power and allowing them to use any unique abilities the being absorbed may have had.

In fact, the main reason for Xion's creation was for her to absorb Roxas and become "the new Sora", thus preventing the real Sora from ever awakening from his sleep. Also, Riku Replica absorbed Zexion's energy in Kingdom Hearts Re:Chain of Memories, something that was encouraged by Axel. This indefinitely made Zexion fade as his power seeped out, and in turn, this made Riku Replica obtain more power.

Notes & Trivia

 * Both the Shadow and Chaos Replicas are the only two Eggman Army replicas that do not have their own boss fight in Sonic Forces.
 * Chaos is the only replica who only appears in the cutscenes of Sonic Forces without involving the battle in the gameplay, as Zavok and Metal Sonic were full-fledged boss fights, and while the Shadow replica is never fought as a boss battle, he does nonetheless appear at the very end of Sunset Heights during gameplay.
 * After both Sonic and the Avatar defeated Infinite, an army of "Infinite replicas" were fighting against the Resistance.
 * However the replicas of Infinite were not seen during the cutscene. They were, however, observed during the first Infinite boss battle.
 * Although Shadow and various other characters stated that the replicas lacked the heart and soul of the originals, it seems that they at the very least possessed the memories of the original, as the Zavok Replica when defeated by Sonic yells "No! How could I lose to the likes of you again?!", alluding to their previous encounter.
 * Despite having slitted pupils in-game, the Shadow replica has normal eyes in promotional artwork and the E3 Trailer. Though it's possible that he has slitted pupils in-game so the player can tell him and the real Shadow apart.
 * In the early game script for Sonic Forces, Mephiles replicas appeared during the battle at Eggman Empire Fortress.
 * In the early game script for Sonic Forces, Sonic believes that the Metal Sonic fought as a boss is not a replica.