MU Online Season 15 Guide

Season 15 (2019-2020) is the biggest content season since the Grow Lancer. It adds the Slayer, a short-sword assassin who is the first new class since Season 14, together with the Blue Eye 5th mastery weapons and the Ancestral Silverheart 6th mastery armour, two new hunting grounds in the Scorched Canyon and Crimson Icarus with elite zones in both, the Ice Dragon 2nd Guardian, the Earring of Honour, Excellent socket necklaces, a rebuilt personal store, the Helper Plus auto-hunt system, and a full Dark Knight renewal that splits the class into a Rage Knight and a Faith Knight.

The Slayer — the new class

The Slayer is a composite life-form: a human from Lorencia rebuilt by Kundun into a half bat-demon. It fights with a short sword, throwing the blade at range and closing on packs at high speed. It needs no unlock — the class is available from the start and begins in Lorencia.

Desmodus is a grade 3 muun exclusive to the class. Its base ability lets the muun use attack skills (not in PvP) and its 30-day period ability doubles muun attack-skill speed. It is grown through the class-change quests: the 1st, 2nd and 3rd class-change quests each hand back a level 1 Desmodus, and the 4th class-change quest gives a Desmodus Evolution Stone.

Skills

The Slayer borrows five Dark Knight skills — Twisting Slash, Uppercut, Lunge, Cyclone and Rageful Blow — and adds four of its own.

Two more skills arrive with the mastery tiers. Detection enhancement (10/10) widens Detection to 500 tiles, and Demolish — bought for Ruud from Priest James in Elbeland, requiring level 400, Agi 1,450 and Master Slayer — spends 3% of your own skill attack power to give you and the party a partial ignore-defence effect for 40 seconds on a 60 second cooldown. Its two master skills cut the cooldown and raise the ignore-defence value.

Starter gear comes from Wandering Merchant Alex (115, 120) in Lorencia, who sells the low-level short swords, wings and the four skill orbs.

Slayer wings and armour

Wings of Silence roll up to two options out of complete mana recovery +5%, complete life recovery +5%, reflect +5% and ignore defence +5%. Wings of Condemnation follow the 4th-wing rules: one to four random options out of eleven, plus zero or one elemental option on top of the elemental defence base.

The Slayer gets a full ladder of its own armour. Socket sets cover the 380–400 band, then the angel tiers run to level 1000.

Defence values, in order helm / armour / pants / gloves / boots. Each tier also has an upgraded four-part version — Harsh Dark Angel, Holy Angel of Punishment, Soul Slayer of Awakening and Frigid Blue Eye — worth roughly ten more defence per piece and carrying the real set bonuses:

The Slayer's own weapon line runs Blood Angel Short Sword (400, 296–306) → Dark Angel (600, 351–361) → Holy Angel (800, 415–425) → Soul (900, 477–497) → Blue Eye (1000, 539–570), all at attack speed 45.

The Slaughterer — the Slayer's 4th class change

The Slayer's 4th class is the Slaughterer. The quest opens at level 800 after the 3rd class change, and is taken from Lorencia NPC Cent (131, 147).

All three of the Slayer's own attack skills get an enhancement branch, each with the same seven nodes. The debuff options and the debuff-explosion passives are the standard ones shared by every class.

Sword Inertia carries the Bleeding and Poison debuffs; Bat Flock and Fierce Attack both carry Poison and Frost.

Blue Eye — the 5th mastery weapons

The 5th mastery tier is the Blue Eye weapon. It is forged at the Chaos Goblin from a Soul weapon enhanced to +11 with 16 options, and the upgrade is 100% — the weapon type, Luck and the Excellent options all carry over.

Every Blue Eye weapon needs level 1,000 and shares one Excellent block: excellent damage rate +10%, attack or magic speed +7, life and mana recovery of (stat/8) per kill, attack or wizardry +2.2 per 20 levels and attack power +62. On the Blue Eye Book the per-20-levels line reads curse power instead.

The Sword, Magic Sword, Bow, Scepter, Claw and Lance keep their skill — Twisting Slash, Power Slash, Triple Shot, Force Wave, Phoenix Shot and Lunge respectively.

Ancestral Silverheart — the 6th mastery armour

The 6th mastery set is Ancestral Silverheart, worn at level 1,100 and upgraded 100% from +11 / 16 option Frigid Blue Eye armour with the Ancestral Soul. The wearing class, equipment slot, Luck and the all-stats option are kept. Silverheart also drops raw in the Scorched Canyon, and the Excellent version drops in Crimson Icarus.

The tier introduces one new option, mastery damage decrease. Like every mastery option it scales with the item's enhancement level, and the growth rate differs by class and by item type.

Defence sits in the 310–365 range on every class. A few examples, in order of the four pieces each class wears:

The energy Elf set is the exception: it trades the damage bonuses for defence improvement +51%, attack power improvement +51%, +45% defence while a shield is equipped, defence +270 and max life +550.

Scorched Canyon

The Kanturu refugees who fled Feria settled in this canyon and began preparing their revenge on Kundun, until the faction that wanted to surrender was turned into Lemuria's soulless soldiers and sent back to destroy the slum. The heroes of MU come here to put those souls to rest.

Later in the season the canyon gained elite zones holding (Elite) Scorched Warrior, Assassin and Wizard. Elite monsters carry elite debuff options and elite skills, and every hit they land applies their elite debuff with a 100% chance.

Crimson Icarus

While the scholars of Medea were still studying Icarus they found a second sky one step below it — a place of red clouds and ill-boding energy that they named Crimson Icarus.

It is an elemental hunting ground, so the monsters carry attributes and have excellent damage rate resistance, critical damage rate resistance, damage absorption and debuff rate resistance.

Five elite zones sit inside the map, one per element: fire (41, 18), water (52, 205), earth (157, 20), wind (148, 206) and dark (188, 98). Each holds (Elite) Crimson Giant Drakan and (Elite) Crimson Dark Phoenix at level 500. Elite monsters are immune to the same things boss monsters are, and every attack applies the element's debuff pair.

Those debuffs are reduced by the elite resistance option on your Guardian. Elite monsters also drop four items of their own, some capped per week and reset weekly:

The Earring of Honour

The 3rd mastery earring is the Earring of Honour. Wearing the left and right earring of the same season together gives the season set bonus. The right earring needs level 800, the left level 750, and both enhance to +15 at the Chaos Goblin using refining stones. The earring itself can also be used as a refining-stone material.

It is made by upgrading a 2nd mastery earring with the Refining Mould of Honour from the Ruud shop plus Bless ×20, Soul ×20, Chaos ×1 and Creation ×1. A left earring produces a left earring, a right produces a right. A failure destroys the materials and drops the earring to +0. The options are rerolled by the upgrade — an earring with three options keeps at least two.

Excellent socket necklaces

Four necklaces arrive that carry Excellent options and sockets — up to three of them, holding water, wind and earth seed spheres only. Mounting and extracting is done at the Seed Master in Elbeland (46, 242). They cannot be put through refining-stone combination.

Up to two Excellent options roll from: excellent damage rate 10%, attack or wizardry +1 per 20 levels, attack or wizardry power 2%, attack and magic speed +7, and life or mana of (stat/8) on a kill. The socket options are the usual defensive list — defence, defence success rate, shield defence, damage decrease, reflect, life and mana recovery, max life and mana, max AG, AG recovery and the four stats.

The socket bonus depends on the order of the elements you mount:

They drop with up to two Excellent options and up to three sockets already open, plus a chance of a 0–3% auto life recovery option, in Deep Dungeon 1–5, the Abyss of Atlans 1–3 and Crimson Icarus.

The Ice Dragon — 2nd Guardian

The second Guardian is the Ice Dragon, an inventory-equipped mount worn at level 900. An Ice Dragon (Rare) exists with identical stats and a different colour, obtainable at a low rate from the same combination.

It is upgraded from the 1st Guardian at the Trainer NPC in Lorencia (122, 110), using the Seal of the Ice Dragon from the Ruud shop plus Bless ×20, Soul ×20, Chaos ×1 and Creation ×1. A failure destroys the materials and drops the base Guardian to +0.

Its base options are movement speed increase and attack speed +7. On top of that it rolls one to three normal options — defence per 20 levels and attack, wizardry or curse power per 20 levels (both up to level 1,100), elemental defence and elemental attack power — and exactly one of five elite resistance sets, which is what protects you in the elite zones:

A successful upgrade rerolls the normal options (three become at least two) and always rerolls the elite resistance option. Dismantling a Guardian now returns only the Guardian Enhancement Stone.

Skill enhancement tree improvements

The debuff half of the tree is rebuilt around a magic circle that forms on the character as you keep using skills. It lasts 10 seconds, has a 20 second cooldown, a base debuff success rate of 100, a radius of 6 tiles and a cap of 7 targets, and applies its debuff once per second depending on the monster's debuff defence rate.

The explosion branch detonates an upper debuff with a matching active skill:

Two new explosion options come with it. Explosion range effect spreads the damage to everything in range with no reduction for extra targets, and explosion infection effect passes the debuff to targets within 3 tiles of the one you detonated, stepping them up one stage (normal → poison, poison → intoxication).

Two new side options cover the 4th wings: a passive that raises defence while 4th wings or a cape are equipped, and a debuff passive that raises attack, wizardry or curse power with them equipped. Side options now cap at 40 points instead of 30 at the same stage.

Finally, Shock and Stun are gone, monsters now have a debuff defence rate (shown in the tooltip on mouse-over) instead of a debuff resistance percentage, and every class's Shock/Stun slots were refilled with the three-debuff layout:

Dark Knight renewal

The Dark Knight splits into two builds, each opened by a skill that stays on once used.

The master tree gains Rage of the Sword Mastery (+1 tile of attack range), Strong Faith Enhancement (base defence), three Solid Protection nodes (conversion amount, damage taken on their behalf, party attack power) and two Destruction Strike nodes. Weapon-skill enhancement options were removed and some skills moved. The skill enhancement tree adds branches for Destruction Strike (deadly poison, freeze), Sword Blow (deadly poison, bleeding) and Solid Protection.

Five mastery shields arrive, all carrying the new option damage taken on another's behalf reduced by shield defence × 0.1 — so the higher the shield's defence, the less of your party's damage hurts you.

Each rolls up to two random Excellent options from reflect 5%, defence success rate +10%, max life, max mana and damage decrease — the life, mana and damage-decrease values scale with the tier (165/165/45 on Blood Angel up to 242/242/66 on Blue Eye).

A matching Faith armour line runs alongside them, all requiring Agi 125–135 and Ene 755–769 per piece:

The last two sets have no wear level printed in the original patch note. One more quality-of-life change came with the renewal: mastery swords can now be worn on Strength or Energy — meeting either one is enough.

Levels, enhancement and the event maps

Season 15 raised the level cap twice. Part 1 took it from 1,150 to 1,200, and Part 2 from 1,200 to 1,250. Each cap came with a season reward: reaching 1,150 gave the Elf Queen Runedil muun (skill attack power +15, multiplied 20× for 30 days) and reaching 1,200 gave the Magic Gladiator Gaion Karein muun (elemental defence +10, same 30-day multiplier). Both arrive through the Gremory Case with a 30-day claim window and a 14-day validity once claimed — miss either and the box is gone for good.

Item enhancement moved out of Normal Combination into its own [Equipment Enhancement] button. Everything enhances there from +1 to +15 — normal, Excellent, set, socket, 380, pentagram, wings and capes (1st to 4th, bound or not, plus monster wings and the Cape of Conqueror), mastery gear, and the Earring of Rage and Earring of Ancestors.

Materials register themselves. Up to +6 a radio button picks Bless or Soul; from +7 only Soul is allowed; at +9 the window switches to the +10–15 layout, where the Lucky Charm, Chaos Combination Charm and their elemental versions still have to be added by hand (a Lucky Charm and a Chaos Combination Charm can sit in the window together).

Event map rebanding

Chaos Castle, Blood Castle, Devil Square and Doppelganger were rebanded for the new level cap:

Monster stats, the related quests and the Blood Castle and Devil Square ticket drop levels were all shifted to match.

Personal store renewal

The personal store was rebuilt. It is now a list, not an inventory grid, and buyers can search and buy from stores on every channel and every hunting ground without travelling to them. Sellers can still only open a store in the safe zones of Loren Market, Lorencia, Elbeland, Noria and Devias, and a store closes automatically if the seller moves somewhere it is not allowed.

Registering an item opens a price window; a registered item leaves the inventory. While the store is closed you can click an entry to change its price or withdraw it. Bundle selling is new — two to five items registered together sell as one lot, so five Blood Angel sets for 100 Jewels of Bless change hands in a single trade.

Money and goods now arrive through a Gremory Case — Personal Store tab: 150 items maximum, a 7-day collection window, and about a one minute delay after each trade. Exceeding the cap blocks further selling and buying.

Smaller changes: keyword search from two characters up (autocomplete still handles single characters), searches that distinguish agility from energy Elf items and wizard from knight Magic Gladiator items, per-tier seed sphere search, a ban on pricing a jewel in the same jewel, and the removal of the Jewel of Chaos as a currency entirely. All existing stores were closed and their contents moved into the Gremory Case.

Helper Plus and party improvements

Helper Plus is a crown-shaped button next to the MU Helper button that recruits a party, finds a hunting ground and starts hunting on its own. It runs while you are solo or the party leader — never as a party member — and not in Valley of Loren, Loren Market, the Event Map Square or the Labyrinth of Dimensions.

Each of the four party slots is set to direct registration (type a name and it is invited on start), party matching (registered publicly with your saved settings) or not registered (nobody can take it). Setting all four to not registered gives you solo play.

Hunting grounds of Deventer difficulty or above can be chosen along with the spot and the monster element. Helper Plus searches your own channel first, then the others, moves the party there with Helper delegation, and shuts itself down if no channel has a free spot. Hunting grounds assigned through the MU Helper never overlap between players.

The party system was tightened up around it. Parties now survive everyone logging off — a member with no login for 30 days is dropped, and a leader with no login for 30 days disbands the party. Party members on different channels stay in the party and can use party content, sharing experience and MU Helper buffs once they are in the same place. Helper delegation and auto-move-to-party-member now work across channels and inside Valley of Loren and Crywolf, and you can invite distant friends straight from the friends list.

Party matching gained an Energy Elf required option, which reserves one slot for a character whose Energy is higher than its Agility or is at least 1,500, and a Check Info button that shows a party's composition before you apply.

Live improvements

Simple UI is an alternative layout that replaces the full HUD with a short quick menu you assemble yourself. Opening the full menu puts the bar into edit mode: click a quick-menu button, then the full-menu button you want in its place, or click two quick-menu buttons to swap them. Closing the full menu ends editing.

The rest of the live pass: character slots reorder with the arrow beside each slot (they cannot jump over an empty slot), party health bars turned green so they no longer read as monster bars, the repair, split and dismantle icons were redrawn, and the free channel-move text was brightened.

Lucky items now refine through the inventory Dismantle button instead of a right-click, and equip by right-click as well as drag and drop. Jewels of Extension stack to 10. The MU Helper no longer gets stuck one tile from its starting point when another character is standing there, and it can now repair your Guardian automatically with Jewels of Bless when the Guardian's life drops to 1 — the setting sits under MU Helper [Other settings].