[QXel]

Well, I often use these kind of spells, and as everybody said : they are really efficient and usefull.

But I ask myself for some preferences here, as ragging hearts, etc.
Yes, they cause lot of unrest, but you can easily counter that with a good patrolling tactic : fast and/ or flying troops, rings of warning, watcher, and so.
Tactic I have developped with my blood slaves-hungry EA Abyssians ;o)

So, I prefer the fire-familly spells (from afar and from the sky), or balefull star (cursed the troops!) or leprosis (disease troops), or direct leader attacks (earth attack, infernal disease, or annoying but not deadly seeking arrow).
Everything which directly kill, curse, hurt the enemy.

Well, I confess, I'm a bit direct. Well, brutal. Ok, I prefer USSR-"2 days heavy artillery barrage before huge human waves offensive"-style than stealthy commandos behind enemy lines ...
;o)