Legion

Legion is the name given by EDI to the gestalt consciousness formed by the 1,183 geth programs, as well as the "mobile platform" they reside in. It is a recruitable party member in Mass Effect 2. Legion is voiced by D.C. Douglas

Geth Infiltrator

 * Rank 1
 * Health: +5.00%
 * Weapon Damage: +6.00%
 * Power Recharge Time: -6.00%


 * Rank 2
 * Health: +10.00%
 * Weapon Damage: +12.00%
 * Power Recharge Time: -12.00%


 * Rank 3
 * Health: +15.00%
 * Weapon Damage: +18.00%
 * Power Recharge Time: -18.00%


 * Rank 4 Unlocks choice between Geth Assassin or Geth Trooper
 * Geth Assassin: Legion has become an expert at disassembling organics and synthetics alike, increasing its weapon damage.
 * Health: +15.00%
 * Weapon Damage: +25.00%
 * Power Recharge Time: -25.00%
 * Geth Trooper: Legion has created redundant systems for its critical functions, increasing its health.
 * Health: +20.00%
 * Weapon Damage: +18.00%
 * Power Recharge Time: -25.00%

Dossier
Legion is first encountered while searching for the IFF on the derelict Reaper. It is surprised to find Commander Shepard (to whom it refers as Shepard-Commander) alive, but assists Shepard's team against the husks roaming the dead ship. Eventually, it is knocked out by a husk while opening the way for them to reach the ship's mass effect core. If recovered, it can be sold to Cerberus for research (as intact geth are hard to come by), or brought aboard the Normandy SR-2 and stored under guard in the ship's AI Core. It can then be reactivated, at which point it will join Shepard's team. When Shepard asks the geth its name, it simply states "Geth". Not satisfied, the Commander rephrases the question until EDI steps in and quotes a passage from Mark 5:9 in the New Testament - "My name is Legion, for we are many." The geth believes this to be an "acceptable metaphor" and thus becomes Legion.

Legion is a unique geth mobile platform, designed to operate outside the Perseus Veil and interact with organics directly. To that purpose, it houses 1,183 geth programs, as opposed to the one hundred or so in other platforms, enabling it to operate independently and speak. It was created and dispatched following Commander Shepard's destruction of the Old Machine "Nazara", known to the rest of the galaxy as the Reaper Sovereign, investigating several of the worlds Shepard visited - Eden Prime, Therum, Feros, Noveria, Virmire, Ilos, and a dozen uncharted worlds. Eventually it finds the Normandy crash site on the planet Alchera, salvaging a piece of Shepard's N7 armor and incorporating it into itself to repair damage sustained on Eden Prime after being shot by Alliance soldiers, though it is unable or unwilling to say why it waited that long or why it used Shepard's armor specifically.

Legion's Appearance
Legion presented an opportunity to develop the basic geth design by adding moving parts that allowed it to animate with detailed expressions. The flaps on Legion's head serve the same purpose as eyebrows to form expression, raising to imply surprise or interest and folding forward much like the furrowing of the brow to show concentration. As a result of its artificial intelligence Legion speaks in a straight-forward and robotic fashion, often answering with single words. When using whole sentences its word structure is very organized. In addition Legion regards itself not as a single being, but as an A.I. platform, and consistently refers to itself as "we" along with Shepard and his squad mates calling Legion "it".

Originally added to the concept just for fun, Shepard's N7 armor became an integral part of Legion's appearance and back story. A large hole is visible in Legion's torso—a wound sustained from gunfire while it was on Eden Prime searching for information related to Shepard.

If questioned, Legion reveals that it found the armor while retracing Shepard's steps and ultimately used it to repair the damage it sustained. However, if pressed why it specifically chose to use Shepard's armor above all else Legion becomes evasive and quietly states "no data available". This could show that Legion has the ability to feel humanlike emotions, as it chooses to use Shepard's armor out of its own free will seemingly out of its obsession with Shepard.

Loyalty: A House Divided


After a while, Legion will inform you that geth actually are apathetic towards organics and those fighting organics are "heretics" following the Reapers or, as they call them, "The Old Machines". Legion will tell you that the heretics are developing a virus that will turn all geth into followers of the Reapers and asks you to head to an old, heretic-held quarian space station in order to destroy the virus threatening the peaceful geth. The very reason why Legion was on the Derelict Reaper was to decrypt the virus, which came from Sovereign. You need to fight your way to the central computer core. Once there, Shepard can decide whether to reprogram the virus and use it to free the heretics from Reaper-control or to destroy it and the space station with all heretics on it. If reprogramming is chosen, Legion will inform Shepard that the heretics will return to the geth and their memories incorporated.

After both Legion's and Tali's loyalty missions are completed, they confront each other and, unless a special charm/intimidate conversation choice is used, one of them will lose their loyalty. Note that while the initial charm/intimidate option is greyed out, if the player sided with Tali, there is a renegade option "I lied to her" when speaking to Legion which will restore Legion's loyalty. It is unknown as yet whether the reverse holds true.

Upgrade
You can allow Legion to access the communication system of the ship to obtain a special sniper rifle for him. If you answer "No", you still have the option to decide otherwise later on.

If Shepard doesn't ask about upgrades, the rifle will be added to the research terminal automatically if Legion's loyalty mission is completed.

Suicide Mission
During the suicide mission, Shepard must choose a tech-specialist crew member to unlock the doors to the central sanctum. This specialist has to navigate through the Collector station's vents in order to bypass the station's doors and defenses. Shepard's squad must protect him, her, or it by redirecting heat energy running through the vents at certain points throughout the level. If Legion is loyal, or if Shepard has agreed to help Legion with the "Heretic" station, Legion is an excellent choice to infiltrate the base's vents and unlock the central doors for the rest of the squad, as long as Garrus, Jacob, or Miranda is leading the fire team. If not, Legion (or anyone chosen for this job) will die of a Collector missile to the head.

If it survives the mission, Legion is surprised by Shepard's destroying the Human-Reaper, considering it to be everything the geth aspire to in terms of "unity, transcendence". If Shepard destroys the Collector base, Legion compares it to the geth refusing Reaper technology and states that "perhaps you are not so different from us". If the base was kept, then Legion recommends not using it, believing organic potential is great and should be acheived independently.

Trivia

 * Specifically, Legion's name comes from a story about Jesus Christ from the Gospel of Mark in the New Testament of the Bible. Jesus was traveling when he came across a demon-possessed man who lived by tombs and would tear free of chains if he was bound. When Jesus asked the man his name, the demons within him responded "My name is Legion, for we are many." The demons begged Jesus to send them into a nearby herd of pigs instead of sending them away. Jesus did so, and the demons made the pigs charge off a nearby cliff and die.
 * During Legion's loyalty mission, Legion states that it has 573 processes voting for re-purposing the virus and 571 voting for destroying the station, leading to a total of 1,144. This is 39 fewer than the stated total of 1,183; since Legion mentions earlier that its high-level processes had not reached consensus, one possibility is that some of its lower-level processes do not participate in this decision.
 * Legion will, if prompted by Shepard, play back an audio recording from the geth collective memory, in which an early geth haltingly asks its quarian master whether or not it has a soul. This is the same event referenced by Tali in Mass Effect while narrating the history of the war between the geth and the quarians.
 * When Legion is first sighted, the subtitles will refer to it as "Legion". Every time after that until EDI names it, the subtitles refer to it as "Geth".
 * Legion expresses admiration for EDI, because unlike the geth who are made up of different processes that rely on each other, EDI handles all the functions on the Normandy by herself, though he also questions how she manages the loneliness or as Legion calls it "maintain stability".
 * Since both Tali's and Legion's loyalty missions are optional (as well as traveling to uncharted worlds), Legion is the only Geth player encounters during the main plot. Haestrom also is an optional mission, as you do not have to recruit all characters from the second set of dossiers before progressing to the next part of the main plot.
 * As you recruit one (with Zaeed DLC) or two (without) party members from the second set of dossiers, it is possible to play through without having gone to Haestrom to recruit Tali. I.e. Samara and Thane (Or either with Zaeed.) As such, both of Tali's missions being the sole plot-relevant but not required missions with Geth, certain play throughs will indeed result in Legion being the only Geth encountered in the main plot. Note, that is if you do skip recruiting Tali for the suicide mission even after getting Legion onboard.
 * When using the skill "Geth Shield Boost", Legion will sometimes say "Overclocking kinetic barriers." "Overclocking" is a tech jargon meaning pushing a system's performance beyond its specified characteristics.
 * If asked about the "fate of the heretics," at one point Legion will refer to itself as "I," (instead of the usual "We") saying "...I could review all my time on the Normandy..." This could simply be a writing error, or a deliberate sign that Legion is beginning to understand organic individualism.
 * When hacking turrets in Legion's loyalty mission, it occasionally utters "Executing sudo command." This is likely a reference to the common unix command sudo, which is used to issue a command as a different user, typically administrator or root.
 * If you enter the AI Core on the Normandy, leave the game alone and stand still for a couple of seconds, Legion will do the Robot. Legion will also do this on missions if the game is left to idle for a few seconds.
 * During Legion's loyalty mission, Legion will mention that using the virus to rewrite the heretics will unleash an EMP of 1.21 petawatts. This could be a reference to "Back to the Future", in which the flux capacitor requires 1.21 gigawatts to work.
 * Due to the conflicted and tense relationships that other races and organizations have with the geth, bringing Legion along on certain missions as a squad mate will often result in extra (occasionally humorous) dialogue.
 * It appears that earlier in the development it was considered for Legion to be recruitable early. It even has unique dialogue lines for places like Purgatory, which can be heard if one uses cheats and brings Legion along for the mission. Further expanding on this is a post here that outlines the cut origins of Legion's N7 armour and how he was originally to be a side kick to Liara in the Mass Effect Redemption comic before being replaced, much of the content from Legion's early recruitment mission was recycled for other parts of Mass Effect 2.