Aion: Steel Cavalry, the upcoming expansion for NCsoft’s massively multiplayer online release, is launching for free come Jan. 29, the publisher announced. Steel Cavalry features the new Aethertech class, two additional in-game instances, new skills, along with general balances and improvements.

This is the fourth expansion for the game, following on from last year’s release Aion 4.0: Dark Betrayal which included new zones. Likewise, the instances featured in Steel Cavalry extend the battlefield with dungeons The Illuminary Obelisk and Iron Wall Warfront.

Aion first launched in North America in 2009 as a subscription-based title before becoming free to play both in Europe and North America in 2012.