The Data-Riku is a character that appears in Kingdom Hearts coded and its remake, Kingdom Hearts Re:coded. He is the digital counterpart of Riku, formed from the data contained in the digitized Jiminy's Journal, as well as a vessel for the memories contained within the journal.
When the memories contained within Jiminy's Journal were strewn apart, restoration could not be completed due to the Bug Blox infestation. Of all the memories inside the Journal, Data-Riku was selected to be a vessel to hold the memories together and protect them from corruption. He then transferred King Mickey, Donald, and Goofy into the Datascape to assist him and Sora's digital counterpart in solving the mystery of the strange words that continued to appear in Jiminy's Journal.
An entity that looks just like Sora's friend Riku. He is, however, not the real deal.
Data-Riku was chosen as a sort of ark to keep all the collective data within Jiminy's journal safe from bugs; in a way, he IS the journal now. But even he could not explain the cause of the bugs, so, after adopting Riku's appearance, he "imported" Mickey and friends to help solve the mystery.
Kingdom Hearts coded
Data-Sora encounters a strange figure in a Black Coat on the digital Destiny Islands, who gives him cryptic clues and leads him to a Keyhole. The figure reappears in the data versions of Traverse Town and Wonderland, giving more cryptic messages and occasionally lending Data-Sora assistance as he works to destroy the bugs and corruption in the worlds' data. After debugging the data for Wonderland, Data-Sora follows the figure to Disney Castle, where he meets Mickey, Donald, and Goofy.
At this time, the black-coated man reveals himself to be Data-Riku. He explains that he has been given possession of the memories contained in Jiminy's Journal, and that he brought Mickey, Donald, and Goofy into the Datascape in order to solve the mysterious message, "We must return to free them from their torment", that appeared in the journal.
As Data-Sora continues visiting the worlds in the journal, Data-Riku stays in Disney Castle, guiding Data-Sora through the monitor. When Data-Sora reaches the digital Olympus Coliseum, Data-Riku tells him that the reason he did not reveal himself to Data-Sora earlier is because he wanted him to become stronger. He discusses with Data-Sora whether they are data or artificial, and Data-Riku says that it does not matter as long as they can make an impact to the world and help their friends.
Data-Riku reveals that the reason the monitor kept showing things Jiminy never wrote about is because it shows the journal's sleeping memories, but that even he does not know the reasons for the mysterious messages appearing in the journal, the Bug Blox corruption that appears in the World's in the Datascape, or what is happening to the Datascape itself.
When Maleficent destroys Data-Sora's Keyblade in the digital Agrabah, Data-Riku and Mickey come to help. However, Maleficent and Pete capture Data-Riku and take him to digital Hollow Bastion, where they infect him with bugs. Later, when Data-Sora defeats Pete in Hollow Bastion, he summons the bug-controlled Data-Riku to fight Data-Sora. After Data-Sora emerges victorious, Data-Riku collapses with Bug Blox fused with his body. Mickey arrives and tells Data-Sora that unless all the bugs in his body are destroyed, Data-Riku will never wake up.
Data-Sora uses his Keyblade to enter Data-Riku's data, meeting with Data-Riku's consciousness. Data-Riku leads Data-Sora through his memories to destroy the bugs and to recover his own power. After Data-Sora destroys the source of the bugs, a corrupted version of Data-Riku himself, Maleficent tries to interfere with Data-Riku's recovery. Data-Sora defeats Maleficent, and Data-Riku awakens.
As the data in the journal finishes debugging and collecting, it begins resetting the Datascape to its original form. However, the data version of Sora's Heartless interferes, and the Datascape begins deleting itself. Data-Riku tells Data-Sora about the nature of the Heartless and rescues Pete and Maleficent. After Data-Sora defeats his Heartless, the Datascape is reset, but Data-Riku partitions off part of his data, containing his memories. He then notifies Mickey, Donald, and Goofy of the appearance of a digital Castle Oblivion in the Datascape.
Data-Riku makes one more appearance, in the first White Room in Castle Oblivion. He shows Data-Sora a memory of the real Riku and a comatose heartless Kairi on the Clock Tower and encourages Sora to push forward, even if he finds himself in torment.
Data-Riku takes on the form of Riku as he appeared in Kingdom Hearts and Kingdom Hearts: Chain of Memories. He is mainly seen wearing the Black Coat of Organization XIII, but while his data is full of bugs, he wears the same bodysuit the real-world Riku wears in Dark Mode.
Data-Riku acts in a fairly similar manner to his real-world counterpart. He is shown to care greatly for Data-Sora, even wanting him to become stronger as well. Data-Riku is cool, calm, and collected, much like the real Riku is. Data-Riku's personality also greatly changes to give him a more aggressive persona while under the influence of the Bug Blox, much like what occurred with the real-world Riku when he slowly lost his heart to darkness.
The only major difference between Data-Riku and the real Riku's personalities would be Data-Riku's sense of responsibility due to his being the vessel containing the journal itself. This is demonstrated by Data-Riku's wish to solve the mystery of the strange messages appearing in Jiminy's Journal and also to keep the memories contained within him safe from corruption.
As the vessel of the memories of Jiminy's Journal, Data-Riku has the ability to manipulate data. He has the ability to access the journal's memories, with it becoming easier as the bugs are destroyed. He also is the one who brings Mickey, Donald, and Goofy into the Datascape, and he opens the passage for them to return to the real world.
He can partition his data to protect his consciousness and memories from corruption or deletion, and he creates passages for Data-Sora to enter his memories and to leave his data. Unless there is interference, he can also lock down the data in the journal in case of emergencies.
One of the many similarities between Data-Riku and the real Riku is the arsenal of abilities they can use in battle. Data-Riku can not only use Dark Shield and counter if the barrier he places before himself is hit (something Riku demonstrated during the battle with Roxas in Kingdom Hearts 358/2 Days), but he can also use the deadly Dark Aura ability.
Data-Riku is also capable of vanishing temporarily and striking the ground soon after, causing several Bug Blox to spawn. Data-Riku lastly is able to wield a data version of the Soul Eater, a weapon used in the real world by Riku.
Data-Riku is the first character affiliated with the song Organization XIII (which plays when Data-Riku first enters Disney Castle) to not be a member of the Organization itself. He is also the first character to share another's main theme, since the song Riku plays during the battles with Data-Riku.