Anyone want to tell me where you're getting this phantom 4-second cast time for Soul Fire at? It's a base 2 seconds for ALL specs. Demo can effectively cast it instantly once every 30 seconds (or after hitting a target under 25%). Destro can stack the cast time reduction on Destructive Influence to get an instant Soul Fire, presumably two times (since it stacks up to 40 at -.1sec per stack).