KOS-MOS is a Rare Blade in Xenoblade Chronicles 2. She can grant tremendous power to her Drivers, Rex, Nia, Zeke or Mòrag, and their allies. KOS-MOS uses the light element, wields an Ether Cannon, and acts as an Attacker in battle. She is known as KOS-MOS Re: in the Japanese version.
KOS-MOS is a featured character based on KOS-MOS from the Xenosaga series. She is an armored android combat weapon with an artificial intelligence. Her design is based on the KOS-MOS's Version 1 model from Xenosaga Episode I: Der Wille zur Macht; both the original and redesign are by Kunihiko Tanaka, who also designed Finch. Her cannons' design resembles the Zohar.
KOS-MOS, true to her construction as an AI, has a very robotic and emotionless personality. She prioritizes the safety of Drivers - not only her own - above ordinary people in much the same way as in Xenosaga she prioritizes the life of her creator over other people. She contains a great destructive power which she releases in a manner calculated to do the least excess damage when given combat tasks. This puts her at odds with T-elos, who relishes causing chaos and damage, and the two disagree on almost everything. KOS-MOS is of great interest to Zeke's young cousin Astelle, although she does not reciprocate it until Astelle greatly increases her capacities by giving her a technological overhaul.
KOS-MOS is an android by name but a standard young lady Blade by all else. She is relatively short and muscular; by Xenosaga canon she should have physique identical to T-elos, however this is not true in Xenoblade Chronicles 2. Otherwise her appearance is very similar to her original; she has fair skin, large magenta eyes, and pastel blue hair that falls past her waist. She wears sci-fi style white armor plating on her legs, arms, and torso, with black, red and blue detailing. One of her arms is black, matching her neck brace. She also wears a large white, black, and red helmet which cover her forehead. When fighting, pink energy structures - similar to T-elos' purple ones - appear around her waist, shoulders, forehead and core crystal.
KOS-MOS' core crystal is blue and shaped like a long, downward-pointing triangle. Whilst it would have made thematic sense to match the Zohar's shape, this would have been identical to the Aegis core crystal, and was likely avoided to prevent confusion.
Heart-to-Heart and Blade Quest
KOS-MOS' Heart-to-Heart, "Daybreak", takes place at the Storage Area Entrance of the First Low Orbit Station between KOS-MOS, her Driver, Tora, and Dromarch. They take in the view, and her Driver begins to worry, given the height, about what could happen if the World Tree were to collapse. KOS-MOS informs them that lower altitudes would fall to Alrest's surface, but this high up any debris would either remain in orbit or disperse into space. KOS-MOS relays information about how the Tree was built, although has no idea why she knows this other than it is information stored in her Core Crystal as her name is.
KOS-MOS' Blade Quest, Artificial Intelligence, begins when the party visits the 7th Perimeter Skyport on the World Tree and finds it infested with Blade Bots. KOS-MOS destroys them efficiently but even more remain, so the party decide to go to the Kingdom of Tantal to warn King Eulogimenos of the threat. Upon reaching the Royal Audience Hall a young girl - Zeke's unknown cousin Astelle - demands to be allowed to accompany Zeke on his travels around Tantal. Eulogimenos disagrees, pointing out that the nations beyond Tantal are very unsafe, but she argues that KOS-MOS will protect her. The King is persuaded, and the party move out to the Empire of Mor Ardain to warn Niall about the Blade Bots. Upon reaching Hardhaigh Palace, under attack, KOS-MOS destroys the Bots here too to Astelle's delight. She asks many questions of KOS-MOS about what she is made of and if Astelle can run tests, which KOS-MOS refuses as Astelle is not her Driver. Finally Astelle begs the party to take her down to the Land of Morytha for research purposes, which they reluctantly agree to - just once, on the condition that she then return to Tantal. She agrees, and as soon as the party reach what she was looking for they are ambushed by Guldos in great number. The Guldos are killed quickly but Astelle being in such danger frightens the party, especially Zeke, and they take her home quickly. Astelle asks that KOS-MOS come and see her a little after arriving back, and upon doing so KOS-MOS finds that Astelle has built her an upgrade that will allow her to function at higher capacity. KOS-MOS is grateful for this, and agrees to be Astelle's friend.
- Lvl.1 - R-Blade - Puts enemies into a hornet's nest by spraying out bullets.
- Lvl.2 - H-Effect R - Develop the Hilbert Effect and change the course of battle.
- Lvl.3 - F-G-Shot - After charging energy, shoot out scattered laser beams.
- Lvl.4 - X-Buster - Fire a concentrated laser beam, but only when energy reserves are full.
- Recharge Boost - Boosts Arts recharge from auto-attack.
- Arts Plus - Boosts power of next Driver Art.
- Critical Up - Increases critical hit rate.
- Phase Transition Tech - Annuls enemy defense and increases Special damage dealt by 60% to 100%.
- Hyperclock - Deal 60% to 100% more damage and take 10% to 30% less damage at max affinity.
- Encephalon - Reduces aggro build-up from attacks by 20% to 40%.
- Light Mastery - Lvl. 3
- Lockpicking - Lvl. 3
- Mental Arithmetic - Lvl. 3 (Skill exclusive to KOS-MOS)
- Pouch item types: Staple Foods, Board Games
- Pouch items: Master's Curry (Staple Foods), Gladiator Wrestling (Board Games)
|Type||Name||Skill Level||Affinity Level||Effect||Prerequisite||Count||Flavor Text|
|Key Affinity Reward||1||1||Affinity Chart level 1 unlocked|
|2||2||Unlocks level 2 of the Affinity Chart||Increase Trust||100||"Expansion of main system functions is complete."|
|3||3||Unlocks level 3 of the Affinity Chart||Increase Trust||1,300||"Enhancement of main system functions is complete."|
|4||4||Unlocks level 4 of the Affinity Chart||Increase Trust||3,800||"Update of main system functions is complete."|
|5||5||Unlocks level 5 of the Affinity Chart. Affinity bond will be easier to sustain.||Go to the 7th Perimeter Skyport, World Tree and complete the quest "Artificial Intelligence".||"I offer thanks to you, Master."|
|Blade Special||R-Blade||1||1||Increases critical damage by 25%|
|2||2||Increases critical damage by 40%||Defeat a Wood Bunnit in Gormott||5||"Clean up complete. Battle systems enhanced."|
|3||3||Increases critical damage by 55%||Use R-Blade||11||"Battle systems enhanced."|
|4||4||Increases critical damage by 70%||Use R-Blade||12||"Battle systems enhanced. Firepower increased."|
|5||5||Increases critical damage by 85%||Use R-Blade||13||"Battle systems enhanced. Diagnostics indicate further expansion may be hazardous."|
|H-Effect R||1||1||When landing a hit, restores 30% of damage dealt to the whole party|
|2||2||When landing a hit, restores 35% of damage dealt to the whole party||Perform a Blade Combo||5||"Weapon systems enhanced. Enhancements are available in future battles."|
|3||3||When landing a hit, restores 40% of damage dealt to the whole party||Use H-Effect R||8||"Weapon systems enhanced. Battlefield capabilities improved."|
|4||4||When landing a hit, restores 45% of damage dealt to the whole party||Use H-Effect R||9||"Weapon systems enhanced. Mobility systems have been optimized."|
|5||5||When landing a hit, restores 50% of damage dealt to the whole party||Finish an enemy||40||"Weapon systems enhanced. Diagnostics indicate further enhancement may be hazardous."|
|F-G-Shot||1||1||Adds a 60% chance of dealing a guard-annulling attack|
|2||2||Adds a 70% chance of dealing a guard-annulling attack||Use F-G-Shot||5||"Ether conversion rate increased. Output has been significantly boosted."|
|3||3||Adds a 80% chance of dealing a guard-annulling attack||Perform a Driver Combo (It's enough to just be present)||7||"Locked on to leader's movements. Strategic capabilities will be enhanced in subsequent battles."|
|4||4||Adds a 90% chance of dealing a guard-annulling attack||Use F-G-Shot||7||"Ether conversion rate increased. Battlefield capabilities improved."|
|5||5||Adds a 100% chance of dealing a guard-annulling attack||Defeat a Gerolf Sovereign at the World Tree||4||"Ether conversion rate increased. Diagnostics indicate that further increase would be hazardous."|
|Battle Skill||Phase Transition Tech||1||1||Annuls enemy defense and increases Special damage dealt by 60%|
|2||2||Annuls enemy defense and increases Special damage dealt by 70%||Perform a Blade Combo||5||"Support mode is fully operational."|
|3||3||Annuls enemy defense and increases Special damage dealt by 80%||Perform a Blade Combo||7||"Support systems enhanced."|
|4||4||Annuls enemy defense and increases Special damage dealt by 90%||Perform a Blade Combo||10||"Master, I hope you are satisfied with my performance."|
|5||5||Annuls enemy defense and increases Special damage dealt by 100%||Perform a Blade Combo||12||"Threats met with maximal force."|
|Hyperclock||1||1||Deal 60% more and take 10% less damage at max Affinity||Perform a Blade Combo||2||"Master, a report. New power is ready to deploy on your mark."|
|2||2||Deal 70% more and take 15% less damage at max Affinity||Use KOS-MOS's favorite pouch items (Board Games category)||2||"Thank you, Master."|
|3||3||Deal 80% more and take 20% less damage at max Affinity||At a place in the First Low Orbit Station with a view of the outside, view the Heart-to-Heart "Daybreak"||"Databanks enhanced with new input from Master-Blade conversation."|
|4||4||Deal 90% more and take 25% less damage at max Affinity||Raise Affinity in combat||6||"Analysis systems expanded. Battlefield contribution has been significantly increased."|
|5||5||Deal 100% more and take 30% less damage at max Affinity||Raise Affinity in combat||7||"I will deploy all available resources to support your attack, Master."|
|Encephalon||1||1||Reduces aggro build-up from attacks by 20%|
|2||2||Reduces aggro build-up from attacks by 25%||Perform a Driver Combo (It's enough to just be present)||5||"Superb movement, Master."|
|3||3||Reduces aggro build-up from attacks by 30%||Perform a Driver Combo (It's enough to just be present)||7||"Would you like me to display the results of my strategic simulation?"|
|4||4||Reduces aggro build-up from attacks by 35%||Perform a Driver Combo (It's enough to just be present)||10||"Master. Please remember that you can count on my support."|
|5||5||Reduces aggro build-up from attacks by 40%||Perform a Driver Combo (It's enough to just be present)||12||"Master! I will participate in your assaults."|
|Field Skill||Light Mastery||1||1||The power of a Light Blade.|
|2||3||Defeat a Spanner Bunnit in Mor Ardain||5||"Output increased. Significantly more power resources became available."|
|3||4||Defeat a Gerolf Sovereign at the World Tree||4||"Master, output has increased to the maximal possible value."|
|Lockpicking||1||1||The power to open various things. Works on doors, treasure troves, etc.|
|2||3||Collect stuff||7||"New analysis subroutines became available."|
|3||4||Collect stuff||7||"High-level analysis subroutines became available."|
|Mental Arithmetic||1||1||Perform complex calculations at speed. Skill exclusive to KOS-MOS|
|2||3||Use a Special||11||"Update complete."|
|3||5||Use a Special||15||"Enemy annihilation complete."|
Some point after awakening her, she will start the quest Artificial Intelligence.
Following Pyra and Mythra figures by Good Smile Company, and Siren by Kotobukiya, a KOS-MOS figure made into a 1/7 scale by Good Smile Company and based on her design from Xenoblade Chronicles 2 was announced on July 29th, 2018.
- Within the Xenosaga series, KOS-MOS's eyes often swap between blue and red, signalling whether her original persona, Mary Magdalene, is in control. In Xenoblade Chronicles 2, her eyes are always pink.
- The Pink blades around KOS-MOS are known as a "Gravity Shell" and, according to his Production Note, were added by Kunihiko Tanaka to make her more like a magical girl.