Rain of Fire (Azgalor)

From WoWWiki

This is an AoE spell cast by Azgalor, the fourth boss of the Battle for Mount Hyjal, and the boss preceding Archimonde. This version of Rain of Fire effects a random target within a 40 yard radius. It deals heavy damage to all targets in this radius, and adds a DoT debuff which causes an additional 1600-1700 damage per second for 5 seconds.