I have to post a new plan before going to sleep, so: Plan B
And no to intercepting, we wait for reinforcements, we have nice forts, why not use this two advantages and rush in a battle?
Let's fortify and prepare, our resource base should be ready to defend itself, even when we leave with majority of our army
Servants
1) All Spectres, Sintaurs, fire elementals - Patrol conquered area, avoid big fights
2) Black imps: Help our cult in Barrspring
3) Zombies, banegouls - work in ZWA
Champions
Alyshtr Yrlvnt:
Gets series of harsh and cruel lessons from the father
For example: (Lock Alyshtr in a room, alone, order single Amberash to kill her, stop it if it injuries her too severely. If she lose, scold her and take away red imp for few days.)
But there are more lessons , not less harsh (propose lessons, it's cool... and if she dies, whatever, !!fun!!)
Dal'Kahh the Avaricious:
Train 15 Cultists commanders (better warriors, will command smaller squads)
Unamed Guard:
Get's mutated by Krlnkir Yrlvnt:
Mutate Former Akataki Guard (take a slave, rip his arms, add this arms to the guard). Also, lie to him that he is your son, half demon and his name is Trfosht Yrlvnt (again, it's cool, waiting before he gets totally corrupted is not, IMO)
Zombie working army
1) Build barracks for another 100 slaves\soldiers
2)Dig, many canals near Akataki for; irrigating farms and villages, defense bonuses, slightly draining river downstream
3) Reinforce Akataki palisade with all that dug out earth
Cult
1) Arm at least 40 cultist crossbowers, more - better
2) Run farmsteads in Akataki, stockpile food both in the town and in Barrspring
3) Mining\lumberjacking in Barrspring
4) Forge steel gates similar to Barrspring one, but for Akataki
5) Build a big brewery in Barrspring. It will brew beverages that slowly corrupt and mutate mortals, but is perfectly fine for any demon
6) Torture captives
7) Worship Krlnkr in the CFM
8 ) Aid ZWA
Krlnkir Yrlvnt
1) Summon many new black imps (really, this little buggers can free our cultists and slaves for more important tasks (army\mutating\sacrificing) than mundane work all we need to support them - provide some booze)
2) Summon tentacle monstrosity in the moat of Akataki, it should have easy switch on\off
3) Scan conquered area for sources of evil, no matter how small they are, consume the smallest, remember bigger
4) Aid cult in all it's tasks
5) Aid champions in all their's tasks