The 'fireball' effect here, does not not look anything like a real fireball. But its not really meant to. I like the effect, it look destructive and unearthly.
The 3d mesh behind the special effects was modeled in blender, as was the 'broken' pillars and rubble.
It not unusual for the render of some of my sets to take 20-30 minutes on a dual P4 CPU box with 2GB memory. The reflections, transparencies and refractions in the fireball took nearly a full day to render.