Tried it but I can't get any faster than this. Warboss always jumps up in the air before all of the lightnings can whittle all of its health.
EDIT: Alright I killed Warboss faster by 1 less jump lmao. Now I don't think I can get any faster than this unless there's some special tips.
I'm really loving the various amount of deep mechanics involving Mage build. Its skill having an effect on terrain such as water is really great, hope to see more like that. If it was just a one note OP build with one move spam in every situation I wouldn't even be playing it at all.