Last updated: July 23, 2026

On this page: The Slayer · All Skills · Deathmodus Muun · Gear & Wings · 6th Armor · Blue Eye Weapons · Scorched Canyon · Crimson Icarus · Honor Earring · Socket Necklaces · 2nd Guardian · Blade Knight Renewal · Skill Tree · FAQ

MU Online Season 15 – Slayer, Blue Eye Weapons & Scorched Canyon

Season 15 (2019–20) added the Slayer — a bat-winged short-sword assassin unlike any class before him — with his own skills, wings, armor and a signature Muun. Around him came the Blue Eye mastery weapons and 6th armor, two new maps (Scorched Canyon, Crimson Icarus) with full monster rosters, the 3rd Mastery Earring, socket necklaces, the 2nd Guardian and a Blade Knight renewal. Rebuilt page-by-page from the original patch notes with the original artwork.

The Slayer

The Slayer — key art	In his dark set

Story: born a Lorencia human, remade by Kundun's experiments into a human-bat hybrid — the first successful composite lifeform, stripped of feeling and used as Kundun's merciless assassin. When a mysterious woman restored his humanity — then he learned she was his mother, executed for treason by his own hand — he fled Kundun, now burning to destroy him.

Basic info	Value
Creation	Freely creatable
Start town	Lorencia (low-level gear & skill orbs from the Wandering Merchant Alex, 115/120)
Base stats	HP 130 / MP 10 · STR 28, AGI 30, VIT 15, ENE 10
Class line	Slayer → Royal Slayer → Master Slayer → Slaughterer (4th)
Weapon	Short sword (dagger) — thrown or dashed with to hit ranged groups
Shared weapons	Kris, Short Sword, Katache, Assassin Blade, Blade, Gladius, Falchion, Serpent Blade, Double Blade
Set party	Slayer + Blade Knight + Summoner

The Slayer's Skills

He borrows part of the Blade Knight kit (Cyclone, Uppercut, Pierce, Twisting Slash, Rageful Blow) and adds five of his own. Every attack skill below is Dark-attribute except Detection:

Skill	Requirements	What it does
Sword Inertia 소드 이너시아	Lv 30 / STR 50 / AGI 100 · Dark	Dashes left and right while throwing 3 boomerang short swords that fly out and return; each sword hits once.
Bat Flock 뱃 플로크	Lv 270 / STR 100 / AGI 380 · Dark	Hurls a swarm of bats forward; anything hit takes 2 hits plus damage-over-time for a while.
Fierce Attack 피어스 어택	STR 300 / AGI 1100 · needs Bat Flock + 10 mastery points · Dark	Dashes to the targets, lands 2 melee hits and returns. If the target is suffering Bat Flock's DoT, he finds the opening and adds 2 bonus hits.
Detection 디텍션	Lv 400 / AGI 800 · No attribute	Bat-sonar — detects lifeforms around him and marks them on the minimap for a while. 5-second cooldown.
Demolish (buff) 데몰리쉬	Lv 400 / AGI 1450 · Master Slayer	Spends 3% of his skill attack to give himself and the party an ignore-defense effect. 40s duration, 60s cooldown. Master options cut its cooldown and raise the ignore-defense amount.

Sword Inertia	Bat Flock
Fierce Attack	Detection

The Deathmodus Muun

The Slayer starts with a Special Muun Egg in his inventory — right-click it to hatch Deathmodus, a level-1 grade-3 Muun. Worn, it doubles his Muun attack-skill speed (30-day timed, no PvP). It levels and evolves through his class-change quests:

Class quest	Deathmodus reward
1st / 2nd / 3rd change	+1 Muun level each
4th change	Deathmodus Evolution Stone

Full pet mechanics: Muun guide.

Slayer Gear & Wings

His armor runs the full mastery ladder — multiple set designs across the tiers:

Gold set	Purple set	Red set	Blue set	Soul set

His wings are bat wings. Both higher tiers below are individual, class-exclusive wings:

3rd Wing — Wings of Silence	4th Wing — Wings of Judgment

Wing	Requirement	Stats
Wings of Silence (3rd)	Lv 400, 3rd class change	DEF 60 · Damage increase 39% · Damage absorb 39% · up to 2 random wing options
Wings of Judgment (4th)	Lv 800, 4th class change	ATK 100 · DEF 140 · Damage increase 55% · Damage absorb 43% · 1–4 wing options + an added-element option

Slayer 6th Mastery Armor

The Silverheart Slayer set is the 6th mastery armor — upgraded from the (dark-blue) 5th mastery set via a set-item upgrade combine, keeping your existing options. Requires level 1100.

Silverheart Slayer set — helm, armor, pants, gloves, boots

Piece	Helm	Armor	Pants	Boots
Defense	346	359	351	326
Req level	1100	1100	1100	1100

Set bonuses: 2-Set mastery skill-attack + mastery STR; 3-Set double-damage chance +18% + mastery attack; 4-Set mastery critical/excellent damage, enemy defense ignore +9%, all stats, triple-damage +6%, max HP and damage reduction.

Blue Eye Weapons (5th Mastery)

The mastery ladder climbed again — a Blue Eye weapon for every class, all requiring level 1000 and upgraded from Soul weapons. Each carries the same Excellent line: +10% excellent-damage chance, +7 attack/magic speed, life/mana on kill, +2.2 attack per 20 levels, +62 attack.

Weapon (class)	Img	Damage	Spd	STR / AGI / other	Skill
Blue Eye Sword Blade Master (BK)		552–562	40	994 / 322	Cyclone
Blue Eye Staff Grand Master (DW)		204–218	30	302 / 103 · magic 136%	—
Blue Eye Bow High Elf		704–722	45	204 / 1193	Multi-Shot
Blue Eye Quiver High Elf		507–531	55	197 / 1179	—
Blue Eye Magic Sword Dual Master (MG)		551–561	45	731 / 448 · ENE 156 · magic 80%	Power Slash
Blue Eye Scepter Lord Emperor (DL)		550–564	40	696 / 164 · pet 88%	Force Wave
Blue Eye Stick Dimension Master (SUM)		187–195	30	274 / 108 · magic 138%	—
Blue Eye Book Dimension Master (SUM)		—	50	AGI 192 · ENE 984 · curse 135%	—
Blue Eye Claw Fist Master (RF)		454–464	35	586 / 197	Phoenix Shot
Blue Eye Lance Mirage Lancer (GL)		345–357	40	441 / 315	Thrust
Blue Eye Rune Mace Majestic Rune Wizard		178–183	50	288 / 108 · ENE 1102 · magic 111%	—

Alongside them, the 6th-tier armor (Silverheart sets) continued the upgrade chain for every class at level 1100.

Scorched Canyon

Lore: survivors of fallen Ferea fled through Tarkan and settled deep in the dry Scorched Canyon on the Kanturu border, building the "Kantur Slum" — Kundun's army to the north, Tarkan's monsters to the south. In their labs they borrowed Arca's magic to turn ordinary humans into mages, preparing their revenge. Killing its monsters drops the new Silverheart armor. It has its own elite zone (marked by an elite banner) with (Elite) versions that apply a 100%-chance elite debuff on hit.

Scorched Warrior	Scorched Wizard	Scorched Assassin

Monster	Level	Attribute	Behaviour
Scorched Warrior	470	Fire/Water/Earth/Wind/Dark	Huge melee monster swinging a giant greatsword
Scorched Wizard	470	Fire/Water/Earth/Wind/Dark	Ranged — sweeps its staff for area magic
Scorched Assassin	480	Fire/Water/Earth/Wind/Dark	Melee — strikes hard with sharp claws

Crimson Icarus

Lore: Median scholars studying Icarus discovered the sky was not one realm — a second, lower sky filled with red clouds and an ill omen. They named it the Crimson Icarus and asked MU's heroes to explore it. It's an attribute hunting ground: monsters resist excellent and critical damage. You need wings equipped or a mount to enter.

Map	Entry	Enter Lv	Penalty Lv
Crimson Icarus	Move command (50,000 zen) or walk in via the entrance at Lost Tower (1,238)	1070	1100

Crimson Alkamos	Crimson Megacrust	Crimson Queen Rainer
Crimson Alphacrust	Crimson Phantom Knight

Monster	Level	Behaviour
Crimson Alkamos	490	Ranged attacker
Crimson Megacrust	495	Area attacker
Crimson Queen Rainer	490	Ranged attacker
Crimson Alphacrust	495	Area attacker
Crimson Phantom Knight	500	Melee attacker

Crimson Icarus also has its own elite zone, and drops the Silverheart armor and Excellent Socket Necklaces.

3rd Mastery Earring – Honor Earring

Honor Earring (Right) — Lv 800	Honor Earring (Left) — Lv 750

The Honor Earring is the 3rd mastery earring, following the Ancestor's Earring. Wear the matching left + right pair from the same season for the set effect. Enhance to +15 at the Chaos Goblin (needs jewel-cut stones).

Earring	Req level	Base options
Honor Earring (Right)	800	ATK / magic / curse 172–175 · elemental defense 160
Honor Earring (Left)	750	ATK / magic / curse 132–135 · elemental defense 102

How to get it: upgrade a +11 to +15 2nd mastery earring at the Chaos Goblin using an Honor Jewel Frame (Ruud shop) plus Bless ×20, Soul ×20, Chaos ×1 and Creation ×1. Success is 100% at +15, scaling down to 60% at +11; the combine re-rolls the earring's random options (a 3-option earring keeps at least 2). A left base material yields a left earring, a right yields a right; failure drops it to +0.

Excellent Socket Necklaces

Four new Excellent Socket Necklaces arrived — the first necklaces with sockets. They carry normal Excellent options and open up to 3 sockets that hold Water / Wind / Earth Seed Spheres (fitted and extracted at the Seed Master NPC in Elbeland, 46/242). All require level 850 and cannot be used in jewel-cut combines.

Jade (attack)	Lapis (magic)	Battle Jade (attack)	Battle Lapis (magic)

Necklace	Type	PvP-only option
Jade Necklace	Attack (attack Excellent options)	—
Lapis Necklace	Magic (magic Excellent options)	—
Battle Jade Necklace	Attack	Defense-ignore chance resist 3%
Battle Lapis Necklace	Magic	SD-ignore chance resist 3%

Excellent options (up to 2): +10% excellent-damage chance, +1 attack/magic per 20 levels, +2% attack/magic, +7 attack speed, life/mana on kill. Socket options (up to 3 by socket count) add defense, HP/MP, reflection and stat lines; the seed sphere type grants a bonus option on top.

2nd Guardian – Ice Dragon

Ice Dragon (Lv 900)	Ice Dragon (Rare)

The Ice Dragon is the 2nd Guardian — an inventory-equipped mount at level 900. A rare version has the same stats but a different colour and a lower drop chance.

How to get it: upgrade-combine a +11 or higher 1st Guardian at the Lorencia Trainer NPC (122/110) using an Ice Dragon Seal (Ruud shop) plus Bless ×20, Soul ×20, Chaos ×1 and Creation ×1. Success runs 100% at +15 down to 60% at +11; a successful combine re-rolls the Guardian's normal and elite-resist options, and can rarely yield the rare Ice Dragon. Failure drops the base Guardian to +0.

Blade Knight Class Renewal

The Blade Knight was reworked into two power builds:

Build	New skill	Req	Effect
Rage Knight	Sword Rage 검의분노	STR 1060	Toggle buff — cast once and it stays on; raises attack-skill range and the area of Blow skills.
	Sword Blow 소드블로우	STR 1090	Wide-area damage skill — hits a broad zone, damage scaling with the area struck.
Faith Knight	Strong Faith 강인한 신념	ENE 1040	Toggle buff (needs a shield) — turns him into a Faith Knight, boosting elemental/attribute defense and base defense.
	Solid Blessing 견고한 가호	ENE 1052	Absorbs the party's overflow max-HP into himself as HP, and converts incoming party damage into energy, buffing the party's attack based on damage taken.

The renewal also added new Master and skill-enhancement tree options tuned around these skills.

Skill Enhancement Tree Improvements

Season 15 reworked the skill enhancement tree: a general skill-enhance tab and a new Debuff Burst tab, letting you strengthen debuff-burst damage (Poison Storm, Frozen Flare, Blary Meteor and linked burst skills) and tune damage range, spread and combustion effects.

General skill-enhance tree
Debuff Burst tree

Everything Else in Season 15

Update	Details
Personal shop renewal	Reworked personal shop interface and flow
Helper Plus & party	Helper Plus auto-hunt upgrades and party-function improvements (party keep-alive, etc.)
Live improvements	Character-select screen and general quality-of-life polish
Event map re-leveling	Chaos Castle, Blood Castle, Devil Square and Doppelganger entry levels rebalanced

Continue Reading

Guide	Why it helps
Classes overview	The Slayer among all classes.
Season 14 guide	The Rune Wizard and Soul gear, right before.
Muun guide	The Deathmodus and every Muun.
Ruud guide	Blue Eye, 6th armor and the upgrade frames.
Earrings guide	The full earring ladder.

FAQ

Where can I play Season 15?
Browse the Season 15 private servers listed — the Slayer ships in every later version too.

Is the Slayer strong?
Very mobile — dash-and-throw AoE with Sword Inertia and Bat Flock makes him a fast farmer, and Demolish gives the party ignore-defense in PvP. Agility is his key stat.

What's special about his Muun?
Deathmodus is class-exclusive and doubles his Muun-skill speed — and it grows for free through his class quests, so every Slayer has a strong pet early.

Should I chase Blue Eye weapons?
Yes at endgame — it's the 5th mastery weapon tier, a flat upgrade from Soul, and the base for everything above it.