KMS event · Ended · About these guides
The ended 2026 KMS Challenger World Season 4 offered level-200 growth potions and level-250 growth potions as tier rewards. The season's reward-use deadline was September 30, 2026 at 11:59 p.m. KST, so these are archived choices rather than currently claimable items.
These potions could not be used inside Challenger World. Eligible higher-tier rewards could be claimed in a permitted regular world to build that world's Legion, separately from moving the seasonal character through World Leap.
Potion planning at a glance
The source used the potions for these purposes:
Level-200 potion: obtain an SS-rank Legion characterLevel-250 potion: obtain an SSS-rank effect on a useful class- Initial candidates: Shade, Mercedes, Wild Hunter, Demon Avenger, and Blaster
- Situational candidates: Mechanic, Marksman, Night Lord, Phantom, and Zero
- Confirm the eligible claim world and intended recipient before claiming
The level-250 potion was not automatically best on Mercedes. The source compared Mercedes and Shade against the main character's cooldown interactions and existing Legion roster.
How the level-200 potion was used
A level-200 potion raised an eligible recipient to level 200, providing SS rank and its character effect and contribution to the KMS Legion point system.
It was not for characters already at or above 200. Choose a missing or lower-level useful class, and check the item's full eligibility conditions, including any class-specific story requirements.
Level-200 character-effect examples
| Purpose | Class | Effect at level 200 | Who benefits |
|---|---|---|---|
| Broad damage choice | Shade | Critical Damage +5% | Most characters that deal critical hits |
| Cooldown utility | Mercedes | Eligible skill cooldowns reduced by 5% | Classes with useful affected cooldowns |
| Damage | Wild Hunter | 20% chance for an attack's damage to increase by 16% | Bossing and training |
| Bossing | Demon Avenger | Boss Damage +5% | Boss-focused characters |
| IED | Blaster | Ignore Enemy Defense +5% | Characters short on effective IED |
| Critical Rate | Marksman | Critical Rate +4% | Characters below the required Critical Rate |
| Critical Rate | Night Lord | Critical Rate +4% | Characters below the required Critical Rate |
| Buff Duration | Mechanic | Buff Duration +20% | Classes with important affected buffs |
| Meso acquisition | Phantom | Meso Obtained +4% | Training and meso farming |
| EXP | Zero | EXP Obtained +10% | Accounts still training several characters |
Shade is a broad offensive option because Critical Damage helps most crit-based attackers. Mercedes can be excellent, but not every skill permits this cooldown reduction.
Marksman and Night Lord usually become less urgent once the needed Critical Rate is covered, except for classes with mechanics that convert excess rate into value. Mechanic depends on how much the class benefits from buff duration.
Main-stat character choices
After securing useful special effects, remaining potions could add characters matching the main's stat needs.
- STR: Hero, Paladin, Buccaneer, Cannoneer, Kaiser, Adele, and Ark
- DEX: Bowmaster, Pathfinder, Wind Archer, Kain, and Angelic Buster
- INT: Ice/Lightning, Bishop, Battle Mage, Blaze Wizard, Luminous, Kinesis, Illium, and Lara
- LUK: Shadower, Dual Blade, Night Walker, Cadena, Khali, and Hoyoung
- Mixed stats: Xenon
- All Stats and Max HP: Lethe, the KMS class listed by the source
A standard single-stat character effect is +80 at level 200. Special and mixed-stat effects have their own values; do not apply +80 indiscriminately to every row. Match the recipient to a useful missing effect.
Choosing a level-250 recipient
A level-250 potion could obtain the SSS effect on an eligible character. The source's most general comparison was Shade versus Mercedes, followed by the needs of the actual main.
| Class | Level-200 effect | Level-250 effect | Increment |
|---|---|---|---|
| Shade | Critical Damage +5% | Critical Damage +6% | 1 percentage point |
| Mercedes | Eligible cooldown reduction 5% | Eligible cooldown reduction 6% | 1 percentage point |
| Demon Avenger | Boss Damage +5% | Boss Damage +6% | 1 percentage point |
| Blaster | IED +5% | IED +6% | 1 percentage point in this effect, not necessarily in final displayed IED |
| Wild Hunter | 20% chance for damage +16% | 20% chance for damage +20% | 4 percentage points on the proc's damage bonus, not a guaranteed 4% total damage gain |
| Mechanic | Buff Duration +20% | Buff Duration +25% | 5 percentage points |
| Zero | EXP Obtained +10% | EXP Obtained +12% | 2 percentage points |
| Phantom | Meso Obtained +4% | Meso Obtained +5% | 1 percentage point |
When Shade is a strong candidate
The source favored Shade when:
- The main makes effective use of Critical Damage
- The account bosses on several characters
- A broadly useful damage effect is preferred
- Mercedes offers little useful cooldown improvement for the main
Critical Damage is broadly useful, but compare the actual marginal gain and any already-owned level-250 Shade before committing a rare reward.
When Mercedes is a strong candidate
Consider Mercedes when:
- The main benefits substantially from eligible cooldown reduction
- Useful short-cooldown attacks or utility skills are affected
- The reduction improves the real rotation rather than just a tooltip
- Shade is already level 250
Cooldown effects and exclusions differ by skill. Mercedes is not automatically better than Critical Damage for every class, and percentage reduction is not a flat one-second reduction.
A situational level-250 shortlist
The source reviewed these candidates in this broad order, adjusting it for the main:
- Shade or Mercedes
- Demon Avenger
- Blaster
- Wild Hunter
- Mechanic
- Zero or Phantom
Mechanic moves up for buff-duration-dependent classes. Marksman or Night Lord can help when Critical Rate is still missing, but another source of rate may be easier to obtain. Check excess-rate interactions for classes that have them.
KMS Legion after leaving Challenger World
Seasonal growth support did not replace the destination world's Legion roster. Existing regular-world progression mattered once the seasonal character arrived.
Legion supplied several separate systems:
- Class-specific character effects
- Stats allocated through Legion Points in the revised KMS system
- Legion Coins accumulated through raid power
- Access to the Legion Coin Shop
- A larger eligible roster as Legion rank increased
KMS's June 2026 rework applied B-rank-or-higher character effects independently of manual roster placement. The point roster used the highest-level eligible characters, while raid power used the strongest eligible contributors. This is the revised KMS system, not a universal description of every GMS Legion interface.
Legion Coins are separate from stat points
Creating characters alone does not instantly supply spendable coins. Raid power determines accumulation, and accumulated coins still need to be claimed under the system's rules.
The source's preparation order was:
- Unlock Legion in the intended regular world
- Use eligible potion rewards on useful characters
- Improve their equipment and raid power within a sensible budget
- Claim accumulated raid coins regularly
- Buy useful items from the Legion Coin Shop
Under the revised KMS rules, rank advancement occurs automatically when requirements are met, after relogging or leveling as applicable. It does not require the old coin-paid rank-up process. Check your regional system before following this step.
Before using a potion
Check the following:
- Is this the intended eligible regular world?
- Do you already have that class at level 200 or 250?
- Would this duplicate a class effect you already own?
- Does the main need the effect?
- Is the required Critical Rate already covered?
- Does the main benefit from buff duration or eligible cooldown reduction?
- Is the item still within its use period?
Duplicate characters of the same class do not stack that class's character effect. A missing class effect is generally a better use than creating a redundant copy solely for the same bonus.
Archived reward FAQ
Could these potions be used on a Challenger World character?
The level-200 potion and level-250 potion could not be used inside Challenger World. Emerald-and-higher reward claims also followed destination restrictions: Worlds 1–3 excluded Eos and Helios, while World 4 used Eos and Helios. The season's claim and use deadlines have passed.
Was Mercedes always the best level-250 choice?
No. Compare useful cooldown interactions, Shade's Critical Damage, and the level-250 classes already on the account. The answer depends on the roster and main.
Which classes were useful first for level 200?
The source first considered Shade, Mercedes, Wild Hunter, Demon Avenger, and Blaster, then filled specific Critical Rate or buff-duration gaps with Marksman, Night Lord, or Mechanic.
Was Zero mandatory?
Zero supplied 10% EXP at level 200 and 12% at 250. It was useful for an account still training many characters, but a largely completed roster could gain more immediate bossing value from another effect. Zero's story requirements also needed to be met.