ARC

ARC (Autonomous Reasoning Center) was the mind of the Entity.

Early life
to be added

Imprisonment by SERVEYOUinc
For years, ARC was kept on the SERVEYOUinc-operated United System Research Base, where he was studied and tortured by Dr Ballard. (COMIC: The Sound of Our Voices) It managed to get out and starting reading the minds of the station personnel, which sent them into a coma. Slowly ARC started learning to communicate verbally. (COMIC: Whodunnit?) The Eleventh Doctor recognised these attempts and helped ARC switch completely. After that ARC restored all comatose people to their original state. The Doctor helped ARC escape from his captors and took him to travel in the TARDIS with Alice Obiefune and John Jones. (COMIC: The Sound of Our Voices)

Travels with the Doctor
to be added

Reunion with the Entity
to be added

Abilities
ARC's extremities could significantly elongate.

By touching a person, he could transfer all information from the brain, living a perfectly healthy but comatose body behind. This process could be reversed. (COMIC: The Sound of Our Voices)

Behind the scenes
ARC is both a playable character and an enemy in the Doctor Who: Legacy mobile game.