MU Online Season 9 and the Cross-Server Battle Core

MU Online Season 9 is the Battle Core season. Its Korean launch on December 10, 2013 carried the title Season 9: Battle Core, after a shared battle server where players from different servers met in Chaos Castle and the new Tormented Square. It also opened Urk Mountain, a volcanic hunting ground in Acheron, added Tetra, the fourth sphere level for socket items, and expanded the Muun system. The global service got Season 9 on November 11, 2014.

Season 9 at a glance

• Korean service: Part 1 on December 10, 2013; Part 2 in April 2014.
• Global service: one update on November 11, 2014. There was no global Part 2; Season X came next.
• New class: none; still seven classes.
• New hunting ground: Urk Mountain, Acheron's fourth, with the boss Lord Silvester.
• Headline systems: Battle Core, Tormented Square, Tetra seed spheres, Muun upgrades, widescreen mode, a stat and skill renewal.
• Level cap: 750 in Korea, up from 730. Webzen's global release did not state one.

What was Battle Core in MU Online?

Battle Core was a shared battle server. In Korea, Webzen set up one for MU Online and one for its MU Blue service, and players from every regular server could enter it to fight each other. It hosted Chaos Castle champion battles and a new event, the Tormented Square champion battle, in which teams hunt monsters against the clock for points. Webzen planned regular online tournaments there from January 2014.

Korea's Part 2 reportedly added a Chaos Castle (Battle) mode and Battle Core rewards, and Season X added a second mode, Tormented Square (Battle). Webzen's global guide has a Battle Core page, but its global Season 9 release does not mention the system, so the global start date is unclear.

IGCN's Season 22 files still contain Battle Core, with reward tables for both Chaos Castle modes and both Tormented Square modes, five Tormented Square maps and a switch that opens or closes registration, so whether a server runs it is that server's call. For the regular events, see the Chaos Castle guide and the PvP guide.

What is Urk Mountain in MU Online?

Urk Mountain was Acheron's fourth hunting ground, a volcanic map with tougher monsters than the older grounds. Portals link points inside it to cut walking time, and Korean coverage said it dropped higher-grade pentagrams and socket items. Its boss on the global service is Lord Silvester, and Webzen's release names four kinds of prize from him: tetra crystals, spheres, socket gear and pentagrams.

IGCN's Season 22 map list still includes Urk Mountain, and Lord Silvester is still in the monster list. The leveling spots guide shows where Acheron's maps fit in a route today.

How do you get a Tetra seed sphere?

Tetra is the fourth sphere level, added to the socket system in Season 9 and announced in Webzen's Season 9 release. Webzen's 4 Level Seed Sphere guide and IGCN's item list give the recipe of the time:

1. Farm the sphere. Sphere (Tetra), as IGCN's item list names it, drops from monsters of level 132 and above.
2. Bring a level-3 seed sphere. The Seed Master builds the level-4 seed sphere on an existing level-3 one, not on a bare seed, and the result keeps that sphere's element.
3. Pay the cost. Webzen's guide lists a 10-pack of Jewels of Chaos, a 10-pack of Jewels of Creation and 1,000,000 Zen. A failed attempt destroys everything you put in.
4. Add a Tetra Crystal if you have one. The Minor, Standard and Greater crystals raise the success rate by 30%, 45% or 60%, and Lord Silvester is one place to get them.

Later seasons added level-by-level sphere upgrades on top of this. On the global service, Season 11 Part 2 made seed spheres upgradable up to level 10 in November 2016. The socket guide explains seeds, spheres and socket options as they work on Season 22.

What else changed in Season 9?

Muun mounts and a second slot

Korea's Part 1 added new Muuns and a second slot to equip one. The global Season 9 update packed in more: Muuns you can ride, a skill each Muun fires on its own, an extra slot on the Y key whose Muun stays out of sight but still applies its skill and passive, and NPC Monica in Elbeland, who trades items for Wizardry Stones.

Widescreen and the stat renewal

Season 9 brought a widescreen mode, listed in Webzen's global release and, per fan coverage, already part of Korea's Part 1. Korea's Part 2 reworked stat specialization and skill damage, and global players got the same changes inside Season 9. Korean press also reported changes to PK and basic character settings made at players' request.

Korean Part 2 extras

A fan preview of Korea's April 2014 patch lists more: the Gremory Case, a storage box for event rewards; a completed Fist Master skill tree for the Rage Fighter; an Evolution Monster event; and extra monster spawns plus Dungeon portals to speed up low-level leveling. The Gremory Case and the Evolution Monster event are both still in IGCN's Season 22 files.

What is MU Online Season 9.5?

Not a Webzen release. Korea split Season 9 into two parts, while the global service shipped one Season 9 update and then moved on to Season X, so the official names stop at Season 9 Part 2. Season 9 Episode 2 is how fan sites and server files label Korea's Part 2, and Season 9.5 is a server-file version number. This is how the names line up:

If a server advertises Season 9.5 or Episode 2, read its feature list: the label alone does not tell you what is switched on.

Season 9 vs Season 6: what changed in between?

Players often compare Season 9 with Season 6, the classic private-server version. Two eras sit between them, eX700 and Season 8, and neither added a class, so both versions have the same seven. Almost everything else changed:

• A second region. eX700, the update players call Season 7, opened Acheron; Season 8 added Debenter and Season 9 added Urk Mountain.
• Elements. Pentagrams, Errtels and elemental damage, none of which exist in Season 6.
• Guild war and cross-server PvP. Arca War from eX700, then Battle Core.
• Higher levels. Season 6 stopped at level 400 plus 200 master levels; Korean Season 9 reached 750.
• Economy and comfort. Pandora mining, store search and party matching from Season 8, plus Muun, widescreen and the Tetra sphere.

MU Online Season 9 FAQ

Is there an official MU Online Season 9.5?

No. Webzen released Season 9 as two parts in Korea and as one update on the global service. Season 9.5 is a private-server file label.

When did MU Online Season 9 come out?

On December 10, 2013 in Korea and on November 11, 2014 on the global service, about eleven months later.

What does Lord Silvester drop?

Webzen's global Season 9 release names four prizes: socket gear, spheres, pentagrams and tetra crystals, the optional ingredient of the Tetra seed sphere recipe.

What does a Tetra Crystal do in MU Online?

It raises the success rate when the Seed Master makes a level-4 Tetra seed sphere. Webzen's guide lists three sizes, Minor, Standard and Greater, worth 30%, 45% and 60%.

What was the max level in MU Online Season 9?

750 in Korea, up from 730. Webzen's global release did not list a cap.

Get ready for Season 22 on SilverMU

Battle Core, Urk Mountain and the Tetra sphere still sit in IGCN's Season 22 data, next to nine classes Season 9 never had. SilverMU is a MU Online private server on Season 22 Part 1-1, server files 22.1.1.0. Continue with Season X, step back to Season 8, or browse the full MU Online season history and what Season 22 adds.

Testing is still under way. Final rates and settings come in a news post before launch, and the download page gets the client once it is published. You can create a free account today.