Aww man, Karaz-a-Karak would be an excellent place for the Emperor to show off some Gryphon riding skills. This'd definitely be the biggest battle he and Sigismund would fight together yet.
And Sigismund may gain enough experience and prowess from the battle that he may impress Oskana a smidge more next they meet.
Anyway, now that I am awake I can review what we learned from the update:
1) Terrors are stationed at the Water and Food production sites as part of the defenses.
This is lovely. Hultressa should be able to order them to allow our sabotage teams to pass silently or too stealthily kill the other guards.
The latter would be more of a panic button approach as we don't want to give up that Hultressa is a traitor so early in the game. But if we cannot find any other way through, or the dice forsake us, its worth mention.
2) The different major Stadiums. First one described seems to have the most trained fighters, so it would be our priority to free the gladiators there first.
2a)The second stadium is filled with a mix of Beasts and loads of defenseless men, women and children. From a tactical standpoint we want those beasts dead or running wild in the streets causing chaos. Morally we want those slaves freed, but only if we have secured a path toward a successful slave revolt, otherwise they will just be captured again.
2b) The final Stadium's contents is a mystery box. I suspect that we will find a bunch of unique personages in there. Sisters of Averlorn, Longma riders from Cathay, Merchant Princes, Priests, etc. Unique, possibly important people for the sadists controlling that Arena to create customized acts of torture and horror for. Probably our best bet to find more Hero unit type characters that will help us on the Ark.