David Archer

David Archer is the brother of Cerberus chief scientist Dr. Gavin Archer.

David Archer is voiced by Jesse Gervais

Overlord
David was born an autistic mathematical savant. Present on Aite during Cerberus' Project Overlord, it was discovered that David was able to communicate with the geth on a fundamental level by reproducing their patterns of speech. As part of attempts to exploit the geth's religious tendencies, Cerberus had created a VI to serve as an "overlord" and give the organization complete control over all geth. Desperate to avoid the project's failure, Gavin Archer forcibly incorporated David into the VI program, exploiting his savant ability. After this point, David's high-functioning autism couldn't handle the merger, causing the hybrid VI to go berserk and begin rampaging across Aite in an attempt to escape the planet. As a hybrid human/VI David can interface with and control any kind of machinery, including security mechs and geth. He is also capable of interfacing with cyborgs, at least to a certain degree, as he imprints memories and visual data directly onto Commander Shepard in order to show the Commander the events leading up to his forced merging with the VI platform.

Aftermath
Commander Shepard's deactivation of the rogue VI program freed David from its effects.

If the Commander followed the Paragon route, David was subsequently removed from the care of Cerberus and his brother and taken to Grissom Academy, an Alliance educational institution for gifted children.

If the Commander followed the Renegade route, David was given medical treatment, stayed in his brother's care and Project Overlord was continued.

He will be encountered in Mass Effect 3 during the Cerberus attack on Grissom Academy if Commander Shepard followed the Paragon route. This will allow Shepard to alleviate suspicions from a few academy students hesitant of David's savior's intentions.

Trivia

 * The apparatus used on David while hooked up to the VI may be a reference to Stanley Kubrick's A Clockwork Orange, in which the Ludovico technique used uses similar apparatus, most notably the 'eye opening' wires.
 * In Grissom Academy, David gives Shepard access to a room which he says contains "guns... lots of guns". This may be a reference to the film The Matrix, in which most humans are trapped in the titular virtual reality world.
 * EDI is apparently known to David, because he greets her familiarly if she happens to be on the squad that comes to his aid. Unusually, he doesn't react to the fact that she has an actual body now, whereas Tali and Legion commented on it as soon as they meet EDI.