Xenoblade Chronicles 2 KOS-MOS Guide: How to Get the Rare Light Blade
Maximize your chances of getting KOS-MOS in Xenoblade Chronicles 2 on Nintendo Switch with our optimized farming and bonding guide.
Quick answer
- KOS-MOS is a rare Light-element Attacker Blade obtained randomly by bonding Drivers with Core Crystals.
- Boost your bonding Driver's Luck stat using specialized accessories and common Blades with Luck modifiers.
- Ensure the Driver's Justice Idea stat is their highest to bias the drop toward Light and Dark elements.
- Farm Rare and Legendary Core Crystals by performing Driver Combos and equipping drop-rate boosting Gold Chips.
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Xenoblade Chronicles 2 KOS-MOS: Overview and Stats
In Xenoblade Chronicles 2 on the Nintendo Switch, KOS-MOS is one of the most sought-after Rare Blades in the game. She is a Light-element, Attacker-class Blade who wields an Ether Cannon, making her an exceptionally powerful offensive option for your party.
Beyond her combat capabilities, she possesses valuable Field Skills that assist with exploration and puzzle-solving:
- Light Mastery
- Lockpicking
- Mental Arithmetic
To keep her effective in combat, you will want to utilize her favorite pouch items. KOS-MOS prefers items from the Board Games and Staple Foods categories. Specifically, her favorite items are:
- Gladiator Wrestling (Board Games category, purchased in Fonsa Myma)
- Master's Curry (Staple Foods category, purchased in Fonsa Myma)
Xenoblade Chronicles 2: How to Get KOS-MOS
Unlike some Rare Blades that are tied to specific side quests or guaranteed campaign milestones, KOS-MOS is obtained strictly via random chance when bonding a Driver with a Core Crystal. Because her base drop rate is low, you must optimize your setup to maximize your probability of pulling her.
To prepare for the bonding process, follow these core steps:
Optimizing Your Setup to Maximize KOS-MOS Drop Rates
To overcome the low random drop rate, you must influence the game's bonding algorithm using two primary character stats: Luck and the Justice Idea stat.
Maximize the Luck Stat
The Luck stat directly influences the rarity of Blades obtained, with higher Luck increasing the probability of pulling a Rare Blade like KOS-MOS. Before you begin bonding:
- Equip Luck-boosting accessories to your chosen Driver. Use a combination of a percentage-based accessory (such as a Luck 25% item) and an accessory that grants a flat Luck modifier.
- Engage common Blades that have percentage-based Luck modifiers on your active Driver to push the stat even higher.
Align Your Idea Stats
During Core Crystal bonding, the game checks only your Driver's single highest Idea stat to apply an elemental bias to the pulled Blade. The Justice Idea stat corresponds to the Light and Dark elements.
- Ensure the bonding Driver's Justice Idea stat is at least 1 point higher than their other Idea stats.
- If necessary, use Justice Boosters during the bonding process to temporarily elevate Justice above the other stats. However, note that using multiple Boosters of the same type does not provide a stacking bonus if that Idea stat is already your highest.
- Using Zeke as your bonding Driver is a highly effective strategy, as his Justice stat is naturally higher than his other Idea stats.
| Stat / Item | Effect on Bonding | How to Optimize |
|---|---|---|
| Luck Stat | Increases overall chance of pulling high-rarity Blades. | Equip 25% Luck accessories, flat Luck accessories, and common Blades with Luck modifiers. |
| Justice Idea | Biases the elemental pull toward Light and Dark. | Ensure Justice is the Driver's highest Idea stat. Use Zeke or apply Justice Boosters. |
| Core Crystal Rarity | Higher rarity crystals have better base drop rates. | Focus entirely on Rare and Legendary Core Crystals. |
Farming Core Crystals and Gold Chips
To secure enough Core Crystals for your bonding sessions, you should set up an efficient farming loop. Common Core Crystals quickly become inefficient, especially when you have 10 or fewer Rare Blades left to obtain. At this stage, you should focus primarily on opening Rare and Legendary Core Crystals.
Step 1: Farm Gold Chips
Before farming crystals, obtain Gold Chips to increase your overall item drop rates by 50%. You can farm these chips by traveling to the bottom of Temperantia and defeating the level 62 Zeoth Serprond. Equip these chips to your active party's Blades.
Step 2: Build a Treasure Sensor Team
Equip your active party members with Blades that possess the Treasure Sensor battle skill (such as Adenine) to further boost the drop rates of enemy items.
Step 3: Perform Driver Combos
Perform the Driver Combo sequence to force enemies to drop items, including Core Crystals:
[Break] -> [Topple] -> [Launch] -> [Smash]
Each successful completion of this sequence spawns a set of drops, making it the most efficient way to gather high-rarity crystals.