MU Online Season 21 – What’s New in 2026?

Now the game has moved forward again with MU Online Season 21. This version builds on Season 20 and adds a new holy warrior class, Crusader (Paladin), a new endgame map Aquilas Temple, a fresh tier of Imperial Legendary gear, a higher max level (1750), Deep Dungeon renewal, and new systems like Ability Crystals to push your damage even higher.

This guide explains the big changes in Season 21 in simple gamer English. We split it into three main parts:

If you stopped playing in older seasons, this page shows what changed and where to continue. If you are brand new, it explains why many Season 21 private servers use this version as their main base in 2025.

Part 1 – Crusader Class, Max Level 1750 & Season 21 Speed Start

Season 21 Part 1 is all about the new class and stronger late-game characters. The Crusader arrives as a holy hammer tank, the total level cap goes up, and many servers run a Season 21 “speed” phase so you can reach the new content quickly.

New Character: Crusader (Paladin) – Holy Hammer Frontliner

The Crusader (called Paladin on some servers) is a holy knight who fights with a hammer and shield. You use the power of Lugard’s light to smash enemies, protect your team, and buff everyone’s damage with special auras.

If you enjoy standing in front, face-tanking monsters, and helping your party at the same time, this is probably your Season 21 main.

• Class name: Crusader / Paladin (depending on server)
• Starting town: Elbeland
• Main weapons: one-handed hammers + shield
• Combat role: melee bruiser, party buffer, hard-to-kill frontline
• Difficulty: Easy to start, medium to master

Crusader Stats in Simple Terms

• Strength (STR): main source of physical damage and hammer requirements – keep this high.
• Agility (AGI): attack speed, defense rate and block – helps you tank and hit faster.
• Vitality (VIT): max HP – needed if you want to stand in front and hold packs.
• Energy (ENE): mana and power for Lugard’s buff skills – you need some later for support builds.

Very simple stat plan (works on most Season 21 low / mid rate servers):

• Early game: focus STR for damage and to equip your hammer, then add VIT so you don’t die in one hit.
• Mid game: start investing AGI for attack speed, defense rate and block chance.
• After level ~220: give some points into ENE so you can use Lugard’s Protection comfortably in parties.

Easy PvE build idea: STR > VIT > AGI, with just enough Energy to keep your buff running. For full “party tank” style, you can go “enough STR for gear and skills” then put most points into VIT and AGI, with a small Energy pool for support.

Core Crusader Skills (Hammer Skills + Holy Auras)

The Crusader mixes some classic Dark Knight skills with new holy hammer skills and a unique aura around Lugard’s Protection.

Shared Dark Knight skills:

• Twisting Slash: spin attack around you; your first real AoE for early spots.
• Fury / Destruction Strike: strong single-target hits, good for early bosses.
• Bloodstorm: extra AoE damage when you unlock it – nice for dense spawns.
• Charge: dash toward your target – good for starting combos or chasing in PvP.

Exclusive Crusader skills (Season 21):

• Divine Fall: a hammer of light falls from the sky and hits enemies in front of you. Quick, strong hit; great as an early “finisher” after you gather a pack.
• Holy Sweep: you move while swinging a massive hammer powered by Lugard’s light, hitting enemies in a wide radius. This is your main farm skill once you meet the STR/AGI requirements.
• Sacred Impact: Ruud skill that throws a hammer made of light, damaging up to 8 targets. Late-game nuke for bosses and elite packs when your stats are high.
• Lugard’s Protection: Punishment: buff skill; you summon Lugard’s emblem on the ground and everyone near it gets more skill attack power. Keep it up 100% of the time in parties.

In simple playstyle terms: Holy Sweep to control big packs, Divine Fall for quick bursts, Sacred Impact as your top-end hammer nuke, and Lugard’s Protection always active for your team.

Job Evolutions – From Crusader to Templar Commander

The Crusader grows through multiple job changes, just like other MU characters:

• 1st: Crusader – basic form; uses Twisting Slash, Charge and early Divine Fall. Learn how to pull packs and tank for the party.
• 2nd: Impact Crusader – better hammer skills and stronger AoE; Holy Sweep becomes your main grind tool.
• 3rd: Master Paladin – unlocks the Master skill tree and more Ruud skills; you start building real endgame combos.
• 4th: Sacred Paladin – stronger buffs and defenses; perfect for holding big packs in high-level maps.
• 5th: Templar Commander – final evolution; top-tier tank/support with strong DPS for Siege and Legendary/Imperial gear.

Simple Crusader Combo Ideas

Crusader can use the classic MU Combo system (with a Combo Ring). A basic combo chains three different skills in the correct order for extra damage:

• Charge → Divine Fall → Holy Sweep – jump into the pack, drop the hammer, then spin through everything.
• Twisting Slash → Divine Fall → Sacred Impact – good vs bosses and tanky elites.
• Holy Sweep → Divine Fall → Twisting Slash – safe combo while you already control the spot.

Practice on weak mobs or dummies until the timing feels natural, then use it in PvP and Castle Siege for burst damage.

Season 21 Speed Start – Fast Track for Crusader & Alts

Just like earlier big updates, official MU and many private servers run a Speed Server / Speed Event when Season 21 content goes live. On these servers, you usually get:

• Much higher EXP and drop rates than normal worlds.
• Extra Ruud, boxes and items for level milestones.
• Rewards or transfer options when the speed phase ends (your Crusader can move to the main server with gear and items).

For most players, the best way to try Crusader and Season 21 quickly is to start on a speed-style server, push levels, then move into the main Season 21 world with a geared character.

Max Level 1750 & Season Rewards

In Season 20, endgame was balanced around roughly 1700 total levels. In Season 21, the maximum character level goes up again to about 1750, giving hardcore players more room to grow and min-max.

• More stat and master points for custom damage / defense builds.
• Extra power for endgame maps like Deep Dungeon and Aquilas Temple.
• Season reward systems on many servers (boxes, Ruud, items) for hitting certain level milestones.

If you enjoy long progression, Season 21’s 1700→1750 stretch gives you a real grind target with better rewards on top private and official-style servers.

Part 2 – Aquilas Temple, Imperial (2nd Legendary) Gear & Crusader Equipment

Season 21 Part 1-2 focuses on new endgame hunting zones and stronger gear. The main highlights are the Aquilas Temple map, a new tier of 2nd Legendary equipment (Imperial), and a full gear line for Crusader so the new class has a proper late-game path.

New Endgame Map: Aquilas Temple

Aquilas Temple is a high-level temple-style map added in Season 21. It is designed as one of the last steps in the standard map progression after places like Twisted Karutan, Kardamahal and other late-game zones (exact order depends on your server).

• Theme: ancient floating temple / fortress with Aquila-type monsters (warriors, gunners, magicians and more).
• Entry: usually via Warp menu at high Master levels; meant for well-geared 5th job characters.
• Monsters: tanky mobs with strong ranged and magic damage; good parties and support buffs are important.
• Drops: top-end Mastery and Legendary items, seeds, and materials for high-tier upgrades such as Imperial Stones on many Season 21 servers.

In short: if Deep Dungeon and other late maps start to feel easy, Aquilas Temple is where you go next to push your character and hunt for better gear.

2nd Legendary Equipment – Imperial Weapons & Armor

Season 20 introduced the first Legendary sets (often called Templguard / Temple Guard). Season 21 takes that a step further with the 2nd Legendary tier, commonly referred to as the Imperial set.

High-level idea:

• You craft Imperial weapons and armor by upgrading your 1st Legendary (Templguard) pieces in the Chaos Machine.
• Core mixes usually keep important options (stat requirements and luck), while transforming the item into the stronger Imperial version.
• Materials often include special Imperial Bless-type items, Jewels of Soul, Creation, and Chaos, plus a big Zen cost.
• There are extra upgrade mixes that use Imperial Reinforcement Stones to boost Imperial gear without breaking it, with success chances that can be increased by “luck” systems on most servers.

For players who already completed Legendary / Templguard sets in Season 20, Imperial gear is the next logical upgrade in Season 21. It adds more damage, defense and better options for Siege and PvE.

Crusader Gear Path – From Floor Hammer to Imperial Paladin

Crusader has access to both classic gear and new Season 21 sets. Here is a simple roadmap that works on most Season 21 style servers (names can change a bit, but the idea is the same):

Early Game (1st–2nd Class)

• Hammers: basic quests and drops (Floor Hammer → Conceived/Considered Hammer → any decent excellent hammer). Look for extra damage, attack speed and life after kill.
• Shields: any shield with good defense and block rate – Floor Shield, Conceived Shield, etc.
• Armor: early Crusader-themed sets or generic low sets with HP / Defense / Damage Decrease options.

Mid Game (3rd–4th Class, Mastery Gear)

• Mastery Hammers: Archangel’s Absolute Hammer → Bloodangel Hammer → Darkangel → Holyangel → Soul → Blue Eye → Silver Heart → Manticore → Brilliant → Apocalypse → Lightning.
• Shields: Paladin / Crusader shields that match the Mastery tier (Bloodangel, Darkangel, Holyangel, etc.) with block, defense, HP, and damage reduction.
• Armor Sets: stick to full Mastery sets for strong set bonuses – especially HP, defenses and damage boosts.

Late Game (5th Class, Legendary & Imperial)

• Legendary: Temple Guard / Templguard Crusader sets plus Temple Guard Hammer for early Legendary progression.
• 2nd Legendary: Imperial weapons, shields and armor upgraded from Templguard pieces.
• Options to aim for: % Damage, Excellent Damage Rate, Double Damage, HP, Damage Decrease, Reflect, SD-related options, and extra block.

For Crusader, a good shield plus Imperial or Legendary hammer can matter as much as the armor. Don’t ignore shield upgrades – they are a huge part of your tankiness in Season 21.

Gameplay Improvements & Events in Season 21

Besides new maps and gear, Season 21 also refreshes many “small” things that you will feel while playing:

• Better client performance: faster loading and fewer random errors or crashes on modern Season 21 files.
• Event rewards reworked: classic events often drop more useful jewels and upgrade items, making daily runs less “waste of time”.
• Boss drops tuned: many servers boost bosses like Volt and other raid bosses to give better loot, especially jewels and endgame materials.
• General QoL: clearer tooltips, better warp menu structure, improved event map access, and more comfortable UI layouts on Season 21 clients.

Most of these improvements are small by themselves, but together they make Season 21 feel smoother and more modern to play than older versions.

Part 3 – Deep Dungeon Renewal, Ability Crystals & Season 21 Endgame

Season 21 doesn’t just add a new class and map – it also extends the endgame loop started in Season 20. Deep Dungeon becomes more important, new upgrade items appear, and PvP / Siege balance shifts around Crusader and Imperial gear.

Deep Dungeon Renewal – More Floors, Better Drops

The Deep Dungeon area gets a renewal in Season 21 style files. High floors are now a core part of late-game farming:

• Monsters have more HP and damage, but also give better EXP and drop tables.
• Many high-value materials (Golden Crests, Ability items, seed materials) are tied to Deep Dungeon and linked maps on Season 21 servers.
• Party play is heavily rewarded – tanks pull, casters and archers burn, Crusaders keep Lugard’s Protection and other buffs active.

For a lot of players, the loop becomes: Deep Dungeon → Aquilas Temple → events and bosses → back to Deep Dungeon, while slowly upgrading Legendary / Imperial gear and Ability setups.

Ability Crystals – Extra Damage System for Late Game

Ability Crystals are a high-tier upgrade system used in modern MU versions (including many Season 21 servers). They work together with Ability Cards and Ability Enhancement Stones to add extra damage multipliers on top of your normal build.

In simple terms:

• You hunt for Ability-related drops (Ability Determination, Ability Cards, etc.) in very high maps like Burning Kethotum and other late-game zones.
• These materials are combined in the Chaos Machine to create Ability Crystals and related enhancement items.
• When used, they give extra offensive bonuses that stack with your gear, masteries and buffs – perfect for min-maxing DPS on all classes.

Not every Season 21 private server uses Ability Crystals exactly the same way, but if your server has them, you should treat them as a key part of your final build, similar to endgame jewels.

Season 21 PvP, Guilds & Castle Siege

Castle Siege and big PvP events are still the peak content for many MU players, and Season 21 changes how they feel:

• Crusaders in Siege: they lead the front line, soaking damage, using Holy Sweep in choke points and dropping Lugard’s Protection where the main DPS is standing.
• Imperial & Legendary gear: guilds that finish Imperial sets and strong earrings / wings have a big edge in both defense and offense.
• Ability and Jewels: late-game jewel systems + Ability Crystals create a real gap between fully-optimized siege guilds and casual players – but events and speed phases help you catch up.

Good siege compositions in Season 21 usually mix:

• Tanks: Crusaders, Blade Knights, defensive Illusion Knights.
• Casters / ranged damage: Dark Wizard, Rune Wizard, Alchemist, Elf, Gun Crusher and others depending on server balance.
• Support: Elves and hybrid builds that focus on buffs, heals, and control.

Season 21 Private Servers – What They Add on Top

Many modern MU Online private servers are now based on Season 21 episode files. They keep the official core (Crusader, level 1750, Aquilas Temple, Deep Dungeon renewal, 2nd Legendary Imperial gear) and then customize on top of that:

• Extra jewel systems (Helix-style, Volt, Emperor, custom sockets, etc.).
• Different EXP / drop rates: from hardcore low rate to ultra high “fun” servers.
• Custom invasions, elite monsters and events built around Season 21 maps.
• Reset systems, rankings, and guild reward systems tuned for long-term play.

If you want to explore different Season 21 experiences, look for server lists that show which servers have Crusader, Aquilas Temple, Imperial gear and active Castle Siege scenes.

Quick Start Tips for MU Online Season 21

To finish, here are quick tips so you don’t feel lost when you join a Season 21 server:

• 1. Pick a main class: Crusader for frontline tank/support, Dark Wizard / Rune Wizard / Alchemist for big AoE damage, Blade Knight / Illusion Knight for melee bruiser, Elf for buffs and ranged support.
• 2. Rush basic gear: use starter sets, quest rewards and early Mastery items to reach Bloodangel / similar tier; then aim for Temple Guard and eventually Imperial.
• 3. Learn your server’s upgrade systems: Helix-like jewels, Imperial mixes, Ability Crystals, and custom jewels are your main tools to grow – don’t leave them sitting in storage.
• 4. Follow a sensible map path: early maps → Acheron / Nixies / Deep Dungeon → Kardamahal / Swamp maps (if present) → Aquilas Temple → Elite or custom zones.
• 5. Join events often: Blood Castle, Devil Square, Chaos Castle, Doppelganger and custom events usually give the jewels and materials you need for gear upgrades.
• 6. Don’t play solo forever: Season 21 content is built around parties and guilds. Join a guild, hop on voice chat, and let Crusaders and supports carry your squishy characters through hard maps.

Play MU Online Season 21 – Your Next Adventure

MU Online Season 21 keeps the nostalgic feeling of Lorencia, Devias and the classic maps, but adds a modern layer of systems and content on top: Crusader builds, Aquilas Temple parties, Deep Dungeon renewal, Imperial gear and late-game Ability setups.

If you are thinking about returning, this is a very good moment. You can log in, roll a Crusader or any favorite class, and slowly climb through Master levels, Legendary sets and Aquilas runs – with plenty of PvP and Castle Siege waiting at the top.

Join us at MUOnline AI – one of the top MU Online Season 21 servers – and jump straight into the new content. See you in Elbeland and Lorencia!