When you visit, what he says will depend on your participation in the first Meridell vs. Darigan plot.
If you fought for Meridell or didn't fight at all, he will say:
What are YOU doing here? Just because we're currently at peace with Meridell doesn't mean that you can just swan up here and explore my citadel whenever you feel like it. Now please leave before I summon the guards!
If you fought for Darigan in the first Meridell vs. Darigan plot, he will say:
I must thank you for your help in the past. I lost the battle, but won the war it seems, how... amusing. Now don't hang around too long, I have *things* to take care of...
To show even more gratitude he gives you an avatar! Yes, isn't that spiffy?
Other than the avatar above, Darigan's Chambers serve no purpose. You do learn that the current relationship between Darigan and Meridell is at truce though, perhaps in the future this room may be used in another Meridell plot? Only time will tell...
This article was written by: DragonBeak