Slayer – MU Online Class Guide: Builds, Skills & Evolutions
The Slayer is MU Online's dual-blade assassin: a fast melee class that fights with two short swords, scales with Agility and trades low HP for high burst damage.
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Webzen added it in Season 15 Part 1, on all global servers from 11 August 2020.
On MUOnline.ai it evolves into Royal Slayer, Master Slayer, Slaughterer and Rogue Slayer, with 60,000 max stats on both realms.
Matchups are MUOnline.ai's own PvP rating, not game data.
On this page (9)
Slayer evolution line
- Slayer
- Royal Slayer
- Master Slayer
- Slaughterer
- Rogue Slayer
Names as listed in the server's class table; evolutions upgrade the same class and never change it into another one. Realm rules and the /evoquest command
Slayer at a glance
| Attribute | Slayer on MUOnline.ai |
|---|---|
| Role | Burst melee and duelist |
| Weapons | Two short swords, one in each hand |
| Main stat | Agility (damage, attack speed and skill unlocks) |
| Secondary stats | Strength up to gear requirements, Vitality for survival |
| Evolutions | 5 stages, from Slayer to Rogue Slayer |
| Class wings | Wings of Silence (level 400) |
| Realms | Permanent Realm 5000x EXP, Speed Realm Autumn Edition 99,999x EXP |
| Max stats | 60,000 on both realms |
Values read from the live server files, updated 26 September 2026.
Webzen introduced the class with Season 15 Part 1 (global speed server 14 July 2020, all global servers 11 August 2020) and names the line Slayer, Royal Slayer, Master Slayer and Slaughterer.
MUOnline.ai runs Season 21 Part 3 server files. Skill and item values here come from its SkillList.xml and ItemList.xml.
Evolution path: Slayer > Royal Slayer > Master Slayer > Slaughterer > Rogue Slayer
Each evolution upgrades the same character. The names come from the server's class table; Webzen uses the same names for the first four stages. What each stage adds, per the server's skill and item data:
- 1st, Slayer: Sword Inertia (level 30), Blessing of Experience (level 50) and Wings of Satan (level 150).
- 2nd, Royal Slayer: Bat Flock (level 150), Wings of Dragon (level 215) and the Paring Short Sword.
- 3rd, Master Slayer: Pierce Attack, Detection, Demolish and Rush, the master skill tree and Wings of Silence.
- 4th, Slaughterer: the 4th-class enhancement tree and Wings of Condemnation (level 800).
- 5th, Rogue Slayer: Pierce Attack of Saturation, the Imperial Short Sword and Wings of Eyes (level 1200).
Rogue Slayer is the name used in the server files. In Webzen's own game, the 5th Class Advancement arrived with Season 19-1 on 10 September 2024.
On MUOnline.ai, class upgrades use the /evoquest command (fast class upgrade) listed on the realm hub. Filter the Permanent Realm ranking by class to see active Slaughterers and Rogue Slayers.
Slayer stat builds under the 60,000 cap
The server data makes Agility the Slayer's scaling stat. Pierce Attack needs 300 Strength and 1100 Agility, Demolish 1450 Agility, and the Silver Heart to Imperial Short Swords 195 Strength and 618 Agility.
Strength therefore stops at a small floor of about 300, while Agility keeps paying off up to the 60,000 cap on both realms. The builds below are our recommendations, not a formula.
| Build | 1st | 2nd | 3rd | Last |
|---|---|---|---|---|
| Agility burst (PvP) | Agility | Vitality | Strength to gear needs | Energy |
| Hybrid (PvE) | Agility | Strength (about half your Agility) | Vitality | Energy |
| First reset | Agility to each skill unlock | Strength to 300 | Vitality | Energy |
Agility burst (PvP / duels)
Agility first, Vitality second, Strength only to the highest requirement of your gear and skills, minimal Energy. The class has low HP, so Vitality decides whether your burst lands before you drop. The long version is the Slayer PvP build guide.
Strength-Agility hybrid (PvE farming)
About two points of Agility for every point of Strength gives steadier damage while clearing spots with Bat Flock and Sword Inertia. Keep some Vitality for big pulls.
First-reset build for beginners
- Agility 100 and Strength 50 for Sword Inertia at level 30.
- Agility 380 and Strength 100 for Bat Flock as a Royal Slayer.
- Agility 1100 and Strength 300 for Pierce Attack as a Master Slayer.
- Vitality whenever you keep dying at your spot.
Spend points with /addagi X, /addstr X and /addvit X, or let /addstr auto X add points while you level.
Slayer skills from the server's skill data
Base damage values are from SkillList.xml, before stats, gear and master tree.
Core attack skills
| Skill | Level | Stage | STR / AGI | Mana | Range | Base damage |
|---|---|---|---|---|---|---|
| Sword Inertia | 30 | 1st | 50 / 100 | 5 | 6 | 10 |
| Bat Flock | 150 | 2nd | 100 / 380 | 20 | 6 | 90 |
| Pierce Attack | 160 | 3rd | 300 / 1100 | 30 | 6 | 170 |
| Rush | – | 3rd | – | 200 | 7 | 178 |
| Pierce Attack of Saturation | 170 | 5th | 300 / 1100 | 20 | 6 | 170 |
Sword Inertia is the cheap opener, Bat Flock your first clearing skill and Pierce Attack the main damage skill from the 3rd class. Rush has the highest base damage and the longest reach, at 200 mana per cast.
Buffs and utility
- Detection: level 350, 800 Agility, 100 mana.
- Demolish: level 400, 1450 Agility, 50 mana.
- Blessing of Experience: level 50, 5 mana.
- Shared melee basics: Twisting Slash, Cyclone, Lunge and Uppercut.
Master skill tree highlights
The tree strengthens the class's own tools: Short Sword Strengthener and Mastery, Wings of Silence Attack and Defense Strengthener, Bat Flock Strengthener, Mastery and Enhancement, Pierce Attack Enhancement, Demolish Strengthener and Mastery, and Sword Inertia Strengthener, Mastery and Enhancement. The node-by-node plan is in the Slayer master skill tree guide.
Slayer skills on MUOnline.ai
Learnable Slayer skills read from the server's SkillList: 19 of 210 entries (master-tree and enhancement nodes are on the full skill list).
| Skill | Required level | Class stage |
|---|---|---|
| Lunge (weapon skill) | – | 1st class |
| Uppercut (weapon skill) | – | 1st class |
| Cyclone (weapon skill) | – | 1st class |
| Twisting Slash | – | 1st class |
| Crescent Moon Slash | – | 1st class |
| Stun | – | 1st class |
| Cancel Stun | – | 1st class |
| Swell Mana | – | 1st class |
| Invisibility | – | 1st class |
| Cancel Invisibility | – | 1st class |
| Archangel's will (weapon skill) | – | 1st class |
| Sword Inertia | 30 | 1st class |
| Blessing of Experience | 50 | 1st class |
| Plasma Storm | 110 | 2nd class |
| Bat Flock | 150 | 2nd class |
| Pierce Attack | 160 | 3rd class |
| Anger Strike | 170 | 2nd class |
| Detection | 350 | 3rd class |
| Demolish | 400 | 3rd class |
Short swords, Slayer sets and wings
Short sword ladder
Every Slayer short sword is one-handed, so you carry two. Requirements from the server's ItemList.xml:
| Short sword | Level | STR / AGI |
|---|---|---|
| Flat, Dacia, Cookery | Any | up to 55 / 155 |
| Paring | 380 | 55 / 190 |
| Novakura, Bloodangel | 400 | 53 / 185, 53 / 175 |
| Darkangel | 600 | 53 / 175 |
| Holyangel | 800 | 49 / 162 |
| Soul | 900 | 46 / 151 |
| Blue Eye | 1000 | 192 / 610 |
| Silver Heart, Manticore, Brilliant, Apocalypse | 1100 to 1400 | 195 / 618 |
| Lightning, Temple Guard | 1500 | 195 / 618 |
| Imperial | 1600 | 195 / 618 |
Slayer armour sets
Slayer-only sets follow the same ladder: Slayer Red Wing, Slayer (A), Slayer Demonic (A) and Nightwing early on, then Fidelity (level 380), Trace and Bloodangel Slayer (400), Darkangel (600), Holyangel (800), Soul (900), Blue Eye (1000), Silverheart (1100), Manticore (1200), Brilliant (1300), Apocalypse (1400), Lightning and Temple Guard (1500) and Imperial Slayer (1600).
Wings for the Slayer
| Wings | Level | Stage |
|---|---|---|
| Small Wings of Satan | 1 | 1st |
| Wings of Satan | 150 | 1st |
| Wings of Dragon | 215 | 2nd |
| Wings of Silence (Slayer wings) | 400 | 3rd |
| Wings of Power | 750 | 3rd |
| Wings of Condemnation | 800 | 4th |
| Wings of Eyes | 1200 | 5th |
Full stats for every sword, set piece and wing are on /items. Items marked there as MUOnline.ai custom are exclusive to this server.
Leveling a Slayer on the Permanent Realm and Speed Realm Autumn Edition
- Permanent Realm: 5000x EXP, medium jewel drops, harder bosses, and it stays online for good.
- Speed Realm Autumn Edition: 99,999x EXP, live since 2 October 2026, 16:00 CEST, with easier bosses, more jewel drops and a Blood Angel set in your inventory. It runs for a limited season, then lets you export up to 2 characters to the Permanent Realm.
Compare Permanent vs Speed Realm rates and rules.
The Slayer levels by clearing fast rather than tanking. Use Sword Inertia and Bat Flock, both range 6, to pull packs and kite them. Find spots for your level on /maps.
Type /reset at the reset level; /reset auto needs VIP 5. A grand reset needs 20 resets, level 400 and 50,000,000 zen, with at most 20 grand resets per account per 24 hours on each realm. Track the top Slayers on the Permanent Realm ranking.
Slayer in PvP and events (our rating)
Strong against / weak against
Our PvP rating favours the Slayer against Gun Crusher and Light Wizard and rates Grow Lancer and Rune Wizard as hard matchups.
We rate its burst and mobility the highest among the melee classes, but it is fragile without Vitality and the Wings of Silence defence nodes. It shines in duels and small skirmishes and is weaker in long sieges.
Castle Siege, Arca War and Icewind Valley
Castle Siege on MUOnline.ai lasts 60 minutes, Saturday 21:00-22:00 UTC. Play the Slayer as a flanker, not a front-line holder.
Arca War runs Monday, Wednesday, Friday and Saturday at 01:00, 07:00, 13:00 and 19:00 UTC on the Speed Realm Autumn Edition and at 00:00, 08:00, 14:00 and 20:00 UTC on the Permanent Realm. Icewind Valley starts 8 times a day on the Speed Realm and at 07:30 and 19:30 UTC on the Permanent Realm.
Watch this week's Castle Siege and event times.
In 2026 Webzen Korea rebalanced the Dark Knight, Magic Gladiator, Rage Fighter and Slayer on its Korean service. That patch is not on MUOnline.ai.
Slayer FAQ
When was the Slayer added to MU Online?
Webzen added the Slayer with Season 15 Part 1: on the global speed server on 14 July 2020 and on all global servers on 11 August 2020. On MUOnline.ai it is playable on both realms.
What are the Slayer's evolutions?
Slayer, Royal Slayer, Master Slayer, Slaughterer and Rogue Slayer. Webzen's guide names the first four; Rogue Slayer is the 5th-stage name in the server files.
Which stat should a Slayer build, Agility or Strength?
Agility. Strength is only needed up to about 300 for Pierce Attack and your short swords, while Demolish alone needs 1450 Agility. Add Vitality for survival; both realms cap each stat at 60,000.
Is the Slayer good for PvP on MUOnline.ai?
Yes for duels and small fights, thanks to high burst and range-6 skills, but it is fragile. In the 60-minute Castle Siege (Saturday 21:00-22:00 UTC) it works best as a flanker.
What weapons and wings does the Slayer use?
Two short swords, up to the level 1600 Imperial Short Sword. Its wings run from Wings of Satan (level 150) through its own Wings of Silence (400) to Wings of Eyes (1200).
Does MUOnline.ai have the 2026 Korean Slayer balance update?
No. That combat-balance patch shipped on Webzen's Korean service only. The Slayer on MUOnline.ai uses the skill values on this page, read from the server data.
Is the Slayer a good first character?
It is fast but not the easiest. Beginner guides such as viciadosmu and mutop100 recommend the Dark Knight for its higher base HP; pick the Slayer if you want speed and burst from your first reset.
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