My BLM DPS seems lower than it should be

[Rongway]

If Thundercloud extends the existing thunder by at least 9 seconds, it's worth it. The complication lies in the renewed thunder subsuming a substantial portion of the spell's damage; in this case, a requirement for increased damage is that the new one is not overwritten until at least 9 seconds after the original effect would have worn off.


Here's where it gets complicated. If you have an existing thunder effect, you need to account for when during its duration you used Thundercloud III. If there were 15 seconds left, then casting another thunder any time before that one wears off would ultimately be a damage loss. The later in the original Thunder you used Thundercloud, the earlier during the renewed duration you can apply a filler Thunder and still come out ahead.