[Shovah32]

I can see this as a fun(and far too expensive for the effect, most likely) tactic for LA Ulm.
Get a blood economy running, get black hearts on those stealthy astral mages, use them to horror mark commanders in assassination attempts, with returning if possible.
Then comes the fun part: You send horrors at that province. Horrors who can home in on the now horror marked commanders - although marked and scattered bodyguards might distract them for a while.