Frankly speaking, I can't call this fight a good one. I really, really dislike losing fights due to unexpected bugs. It is very frustrating...
I didn't take my thunderstriking/storming bane lord into this fight planning that you won't expect there will be no storm. And you didn't expect that. I planned rather small loses and what I received in return?
Btw, it seems that I lost the only commander in this fight - a Dakini who was supposed to fly together with the others but became a lone victim of a friendly Bane Fire instead))
As for the falling frost - it didn't work well due to luck and high protection of my sacreds (it does 17 nomral damage while Kala-Mukhas had 18 protection and luck, MR has no effect on it).
Don't know about no arrows from the castle. Maybe, another bug. I can't find any explanation.