Each hurricane raises unrest ~25
Each Baleful Star ~30
(Unless the target is patrolling or has lowered taxes.)
This kind of question can be answered a lot faster by making a little test game than by posting the question and waiting for someone else to make a test game (I just used a test game I always keep around, for just this kind of question)
Raging hearts produces 60 unrest - it is the most effective remote unrest spell and one of the most cost-effective fire rituals.
Blight increases unrest by 15
Locust swarms - by 20
Rain of Toads - by 40
Baleful star - by 30
Hurricane - by 25
Of course, that's why I asked, so as to know what a minimum number of castings at a fort were required to knock it out (assuming no patrol and tax100).
I'm working on a resource denial strategy for various nations actually. Nothing new to most advanced players I'd guess, but an interesting experiment for me.
Number of Castings >= 100 / Unrest Produced by Ritual
Assuming that you hit the capital the enemy will probably lower taxes and start patrol. But I found that the Unrest will raise if you keep casting the same number of castings as initially.