MU Online has grown through more than twenty seasons since 2005 — each one adding characters, maps, wings and systems that change how the game plays. These guides break down what every season introduced, from the classic Season 6 era to the Legendary-gear endgame of Season 21, and what it means for MU Online Season 22, the version our server runs.
Season guides
Season 22The season our server runs2026 · opening early October
Season 1Tarkan, Wings and Level 3802005 – 2006
Season 2Kanturu and Jewel of Harmony2006 – 2007
Season 3Summoner and Master Level2007 – 2008
Season 4Sockets, Laclion and Selupan2008 – 2009
Season 5Quests, sets and Medusa2009 – 2010
Season 6Rage Fighter and master skills2010 – 2011
Season 7Monster wings, socket weapons2012
Season 8Pentagrams, Acheron and Arca War2013
Season 9Battle Core and the Plaza of Trials2014
Season 10Grow Lancer, Ruud and the mastery sets2015
Season 11Feria and level 10 seed spheres2016
Season 12The 4th class change and Nixies Lake2017
Season 134th wings and the Swamp of Darkness2018
Season 14The Rune Wizard and the Guardian system2019
Season 15The Slayer and Scorched Canyon2020
Season 16Gun Crusher and Arnil Temple2021
Season 17Kundun Mephis and Lemuria2022
Season 18Illusion Knight and Artifacts2022 – 2023
Season 195th class change and Abilities2023 – 2024
Season 20Alchemist and Temple Guard2024 – 2025
Season 21Crusader and Imperial gear2025 – 2026