After being defeated in Molten Core, Ragnaros was banished back to the Elemental Plane. He is now located in Sulfuron Keep, his seat of power within the Firelands. He and his armies will be launching a full scale assault on Mount Hyjal, attempting to burn the now-regrowing World Tree. It seems that he has allied with Deathwing, therefore ending his war against Neferian's forces, and uniting them as a single army. He would be one of two Elemental Lords allied with Deathwing, the other being Al'Akir. His assault on World Tree is run by several of his lieutenants (notably Baron Geddon) assisted by troops of the Twilight's Hammer clan and various members of Twilight dragonflight. According to a series of quests in Mount Hyjal, the assault of Ragnaros was repulsed with the help of some recently revived Eternals and Guardians of Hyjal.
He makes an appearance during the quest N [82] The Firelord in Mount Hyjal. He will make another appearance in Patch 4.2.0 as the final boss of the Firelands outdoor raid.