KOS-MOS

KOS-MOS is the central character in the Xenosaga series. She is an anti-Gnosis battle android developed by Vector Industries' First R&D Division and the magnum opus of the KOS-MOS project.

History
KOS-MOS is a female anti-gnosis battle android developed by Vector Industries. In contrast to current Realian technology, she is made up entirely of mechanical parts. She was created by Kevin Winnicot and Shion Uzuki. As her creator, KOS-MOS unconditionally protects Shion. KOS-MOS stands for Kosmos Obey Strategic Multiple Operation Systems. Her serial number is 00-00-00-00-1. She has the ability to activate the Hilbert Effect, which will cause gnosis to be brought into the same reality as the humans they interact with.

Prior to the events of the game, Kevin arranged to provide access to Cherenkov and soldiers of the U-TIC Organization to enter the facility where KOS-MOS was being developed. While Cherenkov hoped to seize KOS-MOS, she instead went out of control, killing not only the U-TIC Soldiers but her developers as well. This included Kevin. This version of KOS-MOS was eventually stopped by Shion by blasting its head off with hand cannon, destroying it, with only her and Cherenkov as the survivors.

Episode I
KOS-MOS begins the game still in development, with Shion traveling into the Encaphalon in order to use a simulator to test her abilities. She was stationed on the Woglinde to help defend it in the event the gnosis arrived. However Shion and the development team have no actual field data on her, as she has solely been used in simulations. When the gnosis attack the Woglinde, KOS-MOS awakens on her own. She is able to ensure the escape of the Vector employees and make her way to Shion along with Allen. As the two head towards the escape pods they are accompanied by the soldier Virgil. When Virgil stands in her line of fire, KOS-MOS kills him, not wanting the reduction in offensive capability that avoiding him would cause. This horrifies Shion greatly. KOS-MOS and Shion are able to defeat additional gnosis in their way and Shion and Allen make their way into an escape pod to depart the Woglinde. As they depart KOS-MOS confirms that the Woglinde didn't capture the original Zohar, but rather an emulator. This information appears to have been transmitted directly to the Red Testament and Vector CEO Wilhelm.

The passenger ship Elsa soon comes across KOS-MOS. She requests they gate jump to Second Miltia and bring her there, threatening to kill them all if they don't do what she says. The Elsa crew reluctantly let her inside. When the Elsa finds Shion's escape pod, KOS-MOS wants to leave it for the Federation rescue vessels to pick up. KOS-MOS relents after Shion threatens to kill herself and Allen, and chaos appears aboard the bridge and requests they recover them. Shion continues to be surprised by KOS-MOS acting on her own as well as following a mission that Shion is not aware of all the details of. KOS-MOS is permitted usage of the ship's generator to replenish her energy reserves. While she rests she is visited by chaos, who asks where the real her exists. She is also visited by Cherenkov, who is frightened by her and pulls out a gun before Shion shows up.

Shion demands and is permitted from her boss the ability to remain by KOS-MOS's side, so she can determine why she is acting on her own. While on board the Elsa KOS-MOS helps with the dishes and fighting off U-TIC soldiers when Ziggy and MOMO board the ship. When the Elsa comes across the Cathedral Ship, KOS-MOS activates the Hilbert Effect, but the Elsa and all its crew members are nonetheless pulled into it. KOS-MOS picks up a signal similar to that of the Zohar Emulator and the party makes their way there. After they find the Emulator and kill Cherenkov, who has turned into a gnosis, the Cathedral Ship starts to fade away, but there is still a massive amount of gnosis in the area. On her own, KOS-MOS travels up the Elsa's elevator and launches an attack that wipes out all the gnosis. During this scene her eyes appear as blue instead of red for the only time in the game.

When the U-TIC Organization frames the Kukai Foundation for the destruction of the Woglinde, the party is able to prove their innocence by diving into the Encaphalon and recovering KOS-MOS' database. Before departing the Encephalon, Shion has a vision of KOS-MOS and the planet Miltia firing at each other, causing a large explosion. They also find Shion tied to a crucifix-shaped stone. When the gnosis attack the Kukai Foundation shortly afterwards, KOS-MOS again activates the Hilbert Effect to assist in defeating them. Using a phase transfer cannon set up for KOS-MOS by Vector, she fires upon the invisible base summoning the gnosis, the Song of Nephilim, revealing it.

When Albedo tries to access the Y-Data, KOS-MOS appears, protecting it, and saying she does not exist for his pleasure. KOS-MOS heads into the Song of Nephilim along with the party, and then Proto Merkabah. As Proto Merkabah starts descending into the atmosphere of Second Miltia, KOS-MOS stays behind to detach the base's sub components. She is able to do so and make it back to the Elsa as it departs, with Ziggy grabbing a hold of her as she jumps right near the ship. As the Elsa descends towards Second Miltia is starts burning up. KOS-MOS jumps off the ship, in front of it, and activates her energy shield in order to cool its descent.

Episode II
At the start of the game, KOS-MOS is brought to Vector's Second R&D Division on Second Miltia by Shion and Allen. There, the supervisor shows them a diagram of the KOS-MOS Tertiary Weapon System being developed for her. Shion agrees to transfer KOS-MOS over to them. As they leave, Shion tells Allen to keep his eye on KOS-MOS. When the party dives into the Subconscious Domain, Allen provides KOS-MOS' data so she can accompany them.

When Shion heads towards Old Miltia in the Dinah, KOS-MOS awakens on her own while at the Second R&D Division and gets onto a craft that she uses to head into space, claiming Shion is calling her. She soon catches up with the Dinah and combines the craft with it, being able to fight off the enemy forces with it. During this her eyes temporarily change to blue again. KOS-MOS accompanies Shion and the others as they make their way through the Ormus Stronghold, then down to Old Miltia and into Labyrinthos. There she destroys the Zohar Control System once it starts to link with U-DO, killing Cecily and Cathe who are connected to the system. At the Omega System, when Albedo starts linking with U-DO, KOS-MOS claims she can hold things off for three minutes and recommends Shion and the others escape. She is able to escape along with the others on the Elsa.

Xenoblade Chronicles 2
KOS-MOS reappears as a Rare Blade in Xenoblade Chronicles 2. She is an extremely hard to get, as there is only 0.1% chance of obtaining her.

Trivia

 * In the Japanese version of Xenosaga and Xenoblade Chronicles 2, KOS-MOS is voiced by Mariko Suzuki, who also voices T-elos in Xenosaga Episode III and Xenoblade Chronicles 2.
 * Along with KOS-MOS' Japanese voice actor, her English voice actor in Xenosaga Episode I and Xenosaga Episode III, Bridget Hoffman, also voices T-elos in Xenosaga Episode III.
 * In the English version of Xenoblade Chronicles 2, KOS-MOS is voiced by Caitlin Thorburn, who also voices Nim and T-elos in Xenoblade Chronicles 2.

Gallery
KOS-MOS