MU Online Season 16 Guide

Season 16 (2020-2021) adds the Gun Crusher, the first gunner class in MU Online, and pushes the mastery ladder two more rungs with Silver Heart weapons and the Roaring Manticore armour. It opens two hunting grounds - Arnil Temple and Ashen Aida - each with its own elite zone, adds the Fierce Lion 3rd Guardian and the Earring of Blood Vigour, rebuilds the elemental system around mastery pentagrams and errtels, renews the Jewel of Harmony from the ground up, reworks the Magic Gladiator into three distinct builds, and finally lets you ride a mount inside town.

The Gun Crusher — the new class

The MU Empire, losing ground to Kundun, secretly founded the Imperial Task Force and raised abducted orphans through brutal training. Fisher, the boy with the fiercest eyes, survived it and lost himself in the process. Appointed Gun Crusher, his first order was to wipe out the monsters around Elbeland.

He is a magic gunner: an Energy-scaling ranged class whose weapon is the magic gun, and the first class in MU whose damage comes from wizardry rather than a blade.

Skills

Fixed Fire arrived later in the season as the class's own buff. It rebalances how stats convert into abilities: a little defence is given up in exchange for attack speed and wizardry damage. Right-click the buff icon to drop it. Its two master options are Fixed Fire Strengthener (1/20) for wizardry damage and Fixed Fire Mastery (1/10) for attack speed.

Gun Crusher trees and gear

The master tree carries Strengthener, Proficiency and Mastery nodes for the class skills. Ice Break and Death Fire gain skill attack power and +1 tile of damage range (Death Fire also +10 attack speed), Dark Plasma gains targets, duration and range, and two Magic Gun nodes raise wizardry damage and double damage chance while a magic gun is equipped.

Each branch runs the standard seven nodes — skill attack power, damage count +1, additional damage rate, target +1, range +1, skill damage and weapon attack power — plus the debuff pair. Dark Plasma carries deadly poison and freeze; Ice Blast and Bursting Flare carry the same two in the other order.

Magic guns

Every magic gun takes the Jewel of Life option additional wizardry damage +4 / +8 / +12 / +16, and the mastery tiers carry the usual Excellent block with wizardry damage per 20 levels rising 1.5 → 1.6 → 1.8 → 2.0 → 2.2 → 2.4 up the ladder.

Armour and wings

The mastery sets are four-piece (helm, armour, pants, boots) and all share the same requirements: Str 293–335, Agi 240–282, Ene 762–818. Set bonuses climb steadily — the Holy Angel four-set gives ignore defence 9%, all stats +20 and base defence +60, while the Manticore four-set converts to mastery options plus triple damage 8%.

Silver Heart — the 6th mastery weapons

The 6th mastery weapon is the Silver Heart, forged 100% at the Chaos Goblin from a Blue Eye weapon enhanced to +11 with 16 options. The weapon type, Luck and the Excellent options carry over.

Every Silver Heart weapon needs level 1,100 and shares one Excellent block: excellent damage rate +10%, attack or magic speed +7, life and mana of (stat/8) per kill, attack, wizardry or curse power +2.4 per 20 levels and +68 flat.

The shield keeps the Faith Knight option — damage taken on a party member's behalf is reduced by shield defence × 0.1 — and rolls base defence +2.4 per 20 levels, reflect 5%, defence success rate +10%, max life and mana +264 and damage decrease 72.

One balance change came with the tier: the Blue Eye Scepter's pet attack power rose from 88% to 96%.

Roaring Manticore — the 7th mastery armour

The 7th mastery set is Roaring Manticore, upgraded 100% from +11 / 16 option Silver Heart armour with a Manticore's Soul. The wearing class, equipment slot, Luck and the all-stats option are all kept. It needs level 1,200.

Two classes break the pattern. The Faith Knight variant swaps the damage lines for critical and excellent damage rate +35% each and Solid Protection party attack power +230. The support Elf trades them for defence improvement +55%, attack improvement +55%, +47% defence with a shield equipped, defence +280 and max life +570.

Mastery Chaos Combination Charms

A bound charm arrived for every mastery tier. It costs 5% off the combination rate but stops the item being destroyed on a failed +10 to +15 enhancement. It cannot be stacked with the normal Chaos Combination Charm. Fragments drop from monsters and 5 fragments make one charm:

The fragments carry a weekly drop cap that resets each week.

Arnil Temple

Arnil Temple served Arnil, the blood-drinking god, in the ancient empire. The priests who built it were demons wearing human faces: they gathered half the continent for a great assembly, revealed themselves, and slaughtered everyone present as a sacrifice to wake their god. Arnil rose, became Lemuria, and it was Lemuria who resurrected the sealed Secneum — Kundun. The temple was destroyed, and what remained of Kundun's servants have held it as a stronghold ever since.

The elite zones sit at fire (34, 187), water (46, 133), earth (162, 81), wind (135, 220) and dark (35, 69), each marked by an elite zone flag. Every elite monster is level 530 and lands its elemental debuff pair with a 100% chance on every hit — which is what makes a Guardian's elite resistance option worth rolling for.

Elite monsters drop the Elite Option Change Fragment, the Sealed Armour Fragment, the Golden Emblem, the Elite Guardian Enhancement Stone and — new this season — the Jewel of Harmony. Fifty Sealed Armour Fragments build one Scratched Blood Angel Armour at the Noria Chaos Goblin:

Ashen Aida

Deep inside Aida the researchers found a place where the forbidden magic never faded. It bleached the soil, the plants and the animals to black and white, and the heroes of MU went in to burn the dark magic out.

The elite zones are at fire (20, 59), water (47, 108), earth (168, 169), wind (97, 161) and dark (226, 130), holding the (Elite) Ashen Golem and (Elite) Ashen Bloody Witch Queen, both level 560. The drop table matches Arnil Temple and adds Garuda's Flame in the 16-2 update — a second 4th-wing crafting material alongside the Golden Crest.

The Fierce Lion — 3rd Guardian

The third Guardian is the Fierce Lion, an inventory-equipped mount at level 1,000. A Fierce Lion (Rare) with identical stats and a different colour drops out of the same combination at a low rate.

It is upgraded from the 2nd Guardian at the Trainer in Lorencia (122, 110) with the Seal of Fierce Lion — 50,000 Ruud from Priest James in Elbeland (32, 239) — plus Bless ×20, Soul ×20, Chaos ×1, Creation ×1. A failure destroys the materials and drops the base Guardian to +0.

Base options are movement speed and attack speed +7, and this season added defence as a base option on the 1st, 2nd and 3rd Guardians alike, scaling with enhancement level. On top it rolls one to three normal options — elemental attack power +120, elemental defence +120, and defence or attack/wizardry/curse power +3 per 20 levels up to level 1,100 — plus exactly one of the five elite resistance sets (fire, water, earth, wind or dark), which is what blunts the elite-zone debuffs. A successful upgrade rerolls the normal options and always rerolls the elite resistance.

The Earring of Blood Vigour

The 4th mastery earring is the Earring of Blood Vigour, upgraded from an +11 to +15 3rd mastery earring with the Blood Vigour Crafting Mould — 25,000 Ruud from Priest James in Elbeland (32, 239) — plus Bless ×20, Soul ×20, Chaos ×1, Creation ×1. Left makes left, right makes right, and the options are rerolled (an earring with three options keeps at least two).

Wearing both sides gives the season mastery bonus: ignore enemy defence +4%, all stats +7, and the new mastery damage +60, which adds flat damage on every hit and grows with the earring's enhancement level. The ladder now runs Earring of Wrath → Ancestors → Honour → Blood Vigour.

The elemental system rebuilt

Season 16 took the pentagram system apart and put it back together. The headline change: a pentagram of any element now accepts errtels of every element, and the elemental engraving restriction on individual skills is gone — an engraved skill keeps its weighting no matter which pentagram you wear.

Percentage options became flat values, so you can read what a line is actually worth:

Stat points now feed elemental attack and defence properly — including stat points granted by items and master-tree options, which previously did nothing for elemental abilities — and the character window shows the against-element numbers as values instead of percentages.

Opposing-element options

Every pentagram now generates an opposing-element attack and defence option by default, which grows as the pentagram is enhanced:

Mastery pentagrams and errtels

Pentagrams and errtels split into normal and mastery grades. A mastery pentagram takes only mastery errtels of the same grade and can be worn from 3rd class change, level 800. The Errtel of Radiance has no mastery grade and fits any pentagram.

Mastery errtels drop the rank system entirely: rank 1 to rank 3 options are all inherited but the rank condition disappears, and a single option level raises every option the errtel holds at once. Mastery errtels also carry set effects:

All of the new combinations run through NPC Adniel in Elbeland (37, 215):

A mastery pentagram carries as many elemental option slots as it has Anger / Blessing / Divinity slots. Anger and Integrity errtels generate attack options, Blessing and Divinity generate defence options, and you cannot generate one that duplicates the pentagram's opposing-element option or an option it already has.

Jewel of Harmony renewal

The Jewel of Harmony was rebuilt from scratch. It no longer works on normal items; instead it works on +9 or higher Excellent, socket and set weapons and armour, and items carrying harmony options can now be traded.

The option lists were rewritten too. Swords now roll strength, agility and energy, attack success rate, attack power, critical and excellent damage, skill attack power, durability, SD decrease rate and convert 5% of mana into attack power; staffs and books get the wizardry and curse equivalents; armour gets vitality, defence, max AG, life and mana, recovery, damage decrease, durability and convert 10% of mana into life.

Values roll inside a range, and the colour tells you which band you hit:

Granting costs 100,000 zen. The window shows the rolled options and the maximum each could reach, and nothing is written to the item until you press Confirm option — so you can look before you commit.

Refining stones changed job completely. They no longer raise option values — they grant a harmony bonus option, and only on an item whose three harmony options all rolled higher or above. A lower refining stone succeeds 10% of the time, a higher one 50%, the bonus steps up a stage on each success, and a failure wipes it:

Stones themselves are now crafted rather than found: a +4 or higher normal item makes a lower stone, an Excellent one makes a higher stone, at a fee of 150,000 zen — and the item is destroyed if it fails. Rough jewels refine at 50,000 zen each. The Jewel of Harmony itself now drops in the elite zones as well as the Kanturu Maya zone, with a weekly cap.

Watch the small print: upgrading a piece of mastery armour resets its harmony options, set items with harmony options cannot be dismantled, and an outlaw who dies and drops such an item loses the options entirely.

Magic Gladiator renewal

The Magic Gladiator split into three playable builds, each opened by a charge buff that stays on until you die or log out.

All three are bought from Tavern Madam Liamon. The wizard build is the interesting one: equip a staff in both hands and part of the off-hand staff's wizardry damage is added to the character.

Chaos Blade, Fire Blood and Ice Blood are 1,000 Ruud each from Priest James in Elbeland. AG costs were cut hard: Blood Attack from 20–24 to 12, Fire Blood and Ice Blood from 28 to 14, and the attack speed you get per point of Agility was improved.

The Flame Strike, Ice Strengthener and Inferno Strengthener trees were removed, Blood Attack and Gigantic Storm nodes moved, and Weapon Mastery no longer demands 10 points in Twisting Slash Strengthener. Each charge buff gained a Strengthener (bigger explosion or nova) and a Mastery (one extra explosion or nova on the third cast), and Two-Handed Sword and Two-Handed Staff Mastery now push double damage rate to 5%.

On the enhancement tree, Chaos Blade gained a branch carrying bleeding and freeze, Havoc Spear one carrying bleeding and deadly poison.

All six run at attack speed 45 and carry the standard Excellent block, with attack power per 20 levels climbing 1.5 → 2.4 and flat attack power 42 → 68.

Levels, the Labyrinth and quality of life

The cap moved twice again: 1,250 → 1,300 in Part 1 and 1,300 → 1,350 in Part 2. Each came with a season reward box delivered through the Gremory Case, with a 30-day claim window and 14 days of validity once claimed.

Both multiply their base ability 20× for 30 days after you pick them up.

The Labyrinth of Dimensions now rolls a random element for its monsters at the moment a league starts, and that element holds for the whole four-week league — click the Dimensional Gate to see which one you drew. Difficulty rose with it, so experience rose to match, and the reward boxes were rebuilt: bound Blessing of Light (lower) went from 3 to 5 in the lower and intermediate boxes, the higher box swapped its lower blessings for 2 higher ones, and gained 50 Sealed Armour Fragments, a (Hero) Blood Angel's Soul and 450 Ruud.

Mounts finally work everywhere. You can ride in towns and safe zones, attacking dismounts you automatically and you remount about 3 seconds after combat ends, and the mount's movement speed is kept even while you are on foot — including after a manual Ctrl+Z. Mount skills became character skills gated on having the mount equipped: Earthshake (Dark Horse), Plasma Storm (Fenrir) and Raid Shoot (Dinorant). Spear Thrust was removed, and expired time-limited items can now be dismantled.

A Bundle button in the inventory merges every stackable item in one click, working from the top left down. And Moss's Boxes were reorganised: the Jewel of Extension and the Gold and Silver Keys came out, and in went three Excellent mastery pieces per box plus ten of each of the eight enhancement elixirs — strength, swiftness, wizardry, life, defence, might, mana and criticals.